extensions/browser/event

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This source file includes following definitions.
DoNothing
NotifyApiEventDispatched
DispatchExtensionMessage
Get
GetBaseEventName
DispatchEvent
listeners_
AddEventListener
RemoveEventListener
RegisterObserver
UnregisterObserver
OnListenerAdded
OnListenerRemoved
AddLazyEventListener
RemoveLazyEventListener
AddFilteredEventListener
RemoveFilteredEventListener
HasEventListener
ExtensionHasEventListener
HasEventListenerImpl
GetRegisteredEvents
SetRegisteredEvents
AddFilterToEvent
RemoveFilterFromEvent
GetFilteredEvents
BroadcastEvent
DispatchEventToExtension
DispatchEventWithLazyListener
DispatchEventImpl
DispatchLazyEvent
DispatchEventToProcess
CanDispatchEventToBrowserContext
MaybeLoadLazyBackgroundPageToDispatchEvent
IncrementInFlightEventsOnUI
IncrementInFlightEvents
OnEventAck
DispatchPendingEvent
Observe
can_load_ephemeral_apps
can_load_ephemeral_apps
can_load_ephemeral_apps
DeepCopy
browser_context
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "extensions/browser/event_router.h"

#include <utility>

#include "base/bind.h"
#include "base/command_line.h"
#include "base/message_loop/message_loop.h"
#include "base/stl_util.h"
#include "base/values.h"
#include "chrome/browser/chrome_notification_types.h"
#include "content/public/browser/notification_service.h"
#include "content/public/browser/render_process_host.h"
#include "extensions/browser/api_activity_monitor.h"
#include "extensions/browser/extension_host.h"
#include "extensions/browser/extension_prefs.h"
#include "extensions/browser/extension_registry.h"
#include "extensions/browser/extension_system.h"
#include "extensions/browser/extensions_browser_client.h"
#include "extensions/browser/lazy_background_task_queue.h"
#include "extensions/browser/process_manager.h"
#include "extensions/browser/process_map.h"
#include "extensions/common/extension.h"
#include "extensions/common/extension_api.h"
#include "extensions/common/extension_messages.h"
#include "extensions/common/extension_urls.h"
#include "extensions/common/manifest_handlers/background_info.h"
#include "extensions/common/manifest_handlers/incognito_info.h"

using base::DictionaryValue;
using base::ListValue;
using content::BrowserContext;
using content::BrowserThread;

namespace extensions {

namespace {

void DoNothing(ExtensionHost* host) {}

// A dictionary of event names to lists of filters that this extension has
// registered from its lazy background page.
const char kFilteredEvents[] = "filtered_events";

// Sends a notification about an event to the API activity monitor on the
// UI thread. Can be called from any thread.
void NotifyApiEventDispatched(void* browser_context_id,
                              const std::string& extension_id,
                              const std::string& event_name,
                              scoped_ptr<ListValue> args) {
  // The ApiActivityMonitor can only be accessed from the UI thread.
  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(
        BrowserThread::UI,
        FROM_HERE,
        base::Bind(&NotifyApiEventDispatched,
                   browser_context_id,
                   extension_id,
                   event_name,
                   base::Passed(&args)));
    return;
  }

  // Notify the ApiActivityMonitor about the event dispatch.
  BrowserContext* context = static_cast<BrowserContext*>(browser_context_id);
  if (!ExtensionsBrowserClient::Get()->IsValidContext(context))
    return;
  ApiActivityMonitor* monitor =
      ExtensionsBrowserClient::Get()->GetApiActivityMonitor(context);
  if (monitor)
    monitor->OnApiEventDispatched(extension_id, event_name, args.Pass());
}

}  // namespace

const char EventRouter::kRegisteredEvents[] = "events";

struct EventRouter::ListenerProcess {
  content::RenderProcessHost* process;
  std::string extension_id;

  ListenerProcess(content::RenderProcessHost* process,
                  const std::string& extension_id)
      : process(process), extension_id(extension_id) {}

  bool operator<(const ListenerProcess& that) const {
    if (process < that.process)
      return true;
    if (process == that.process && extension_id < that.extension_id)
      return true;
    return false;
  }
};

// static
void EventRouter::DispatchExtensionMessage(IPC::Sender* ipc_sender,
                                           void* browser_context_id,
                                           const std::string& extension_id,
                                           const std::string& event_name,
                                           ListValue* event_args,
                                           UserGestureState user_gesture,
                                           const EventFilteringInfo& info) {
  NotifyApiEventDispatched(browser_context_id,
                           extension_id,
                           event_name,
                           make_scoped_ptr(event_args->DeepCopy()));

  ListValue args;
  args.Set(0, new base::StringValue(event_name));
  args.Set(1, event_args);
  args.Set(2, info.AsValue().release());
  ipc_sender->Send(new ExtensionMsg_MessageInvoke(
      MSG_ROUTING_CONTROL,
      extension_id,
      kEventBindings,
      "dispatchEvent",
      args,
      user_gesture == USER_GESTURE_ENABLED));

  // DispatchExtensionMessage does _not_ take ownership of event_args, so we
  // must ensure that the destruction of args does not attempt to free it.
  scoped_ptr<base::Value> removed_event_args;
  args.Remove(1, &removed_event_args);
  ignore_result(removed_event_args.release());
}

// static
EventRouter* EventRouter::Get(content::BrowserContext* browser_context) {
  return ExtensionSystem::Get(browser_context)->event_router();
}

// static
std::string EventRouter::GetBaseEventName(const std::string& full_event_name) {
  size_t slash_sep = full_event_name.find('/');
  return full_event_name.substr(0, slash_sep);
}

// static
void EventRouter::DispatchEvent(IPC::Sender* ipc_sender,
                                void* browser_context_id,
                                const std::string& extension_id,
                                const std::string& event_name,
                                scoped_ptr<ListValue> event_args,
                                UserGestureState user_gesture,
                                const EventFilteringInfo& info) {
  DispatchExtensionMessage(ipc_sender,
                           browser_context_id,
                           extension_id,
                           event_name,
                           event_args.get(),
                           user_gesture,
                           info);

  BrowserThread::PostTask(
      BrowserThread::UI,
      FROM_HERE,
      base::Bind(&EventRouter::IncrementInFlightEventsOnUI,
                  browser_context_id,
                  extension_id));
}

EventRouter::EventRouter(BrowserContext* browser_context,
                         ExtensionPrefs* extension_prefs)
    : browser_context_(browser_context),
      extension_prefs_(extension_prefs),
      listeners_(this) {
  registrar_.Add(this, content::NOTIFICATION_RENDERER_PROCESS_TERMINATED,
                 content::NotificationService::AllSources());
  registrar_.Add(this, content::NOTIFICATION_RENDERER_PROCESS_CLOSED,
                 content::NotificationService::AllSources());
  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_ENABLED,
                 content::Source<BrowserContext>(browser_context_));
  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_LOADED,
                 content::Source<BrowserContext>(browser_context_));
  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNLOADED_DEPRECATED,
                 content::Source<BrowserContext>(browser_context_));
}

EventRouter::~EventRouter() {}

void EventRouter::AddEventListener(const std::string& event_name,
                                   content::RenderProcessHost* process,
                                   const std::string& extension_id) {
  listeners_.AddListener(scoped_ptr<EventListener>(new EventListener(
      event_name, extension_id, process, scoped_ptr<DictionaryValue>())));
}

void EventRouter::RemoveEventListener(const std::string& event_name,
                                      content::RenderProcessHost* process,
                                      const std::string& extension_id) {
  EventListener listener(event_name, extension_id, process,
                         scoped_ptr<DictionaryValue>());
  listeners_.RemoveListener(&listener);
}

void EventRouter::RegisterObserver(Observer* observer,
                                   const std::string& event_name) {
  // Observing sub-event names like "foo.onBar/123" is not allowed.
  DCHECK(event_name.find('/') == std::string::npos);
  observers_[event_name] = observer;
}

void EventRouter::UnregisterObserver(Observer* observer) {
  std::vector<ObserverMap::iterator> iters_to_remove;
  for (ObserverMap::iterator iter = observers_.begin();
       iter != observers_.end(); ++iter) {
    if (iter->second == observer)
      iters_to_remove.push_back(iter);
  }
  for (size_t i = 0; i < iters_to_remove.size(); ++i)
    observers_.erase(iters_to_remove[i]);
}

void EventRouter::OnListenerAdded(const EventListener* listener) {
  const EventListenerInfo details(
      listener->event_name,
      listener->extension_id,
      listener->process ? listener->process->GetBrowserContext() : NULL);
  std::string base_event_name = GetBaseEventName(listener->event_name);
  ObserverMap::iterator observer = observers_.find(base_event_name);
  if (observer != observers_.end())
    observer->second->OnListenerAdded(details);
}

void EventRouter::OnListenerRemoved(const EventListener* listener) {
  const EventListenerInfo details(
      listener->event_name,
      listener->extension_id,
      listener->process ? listener->process->GetBrowserContext() : NULL);
  std::string base_event_name = GetBaseEventName(listener->event_name);
  ObserverMap::iterator observer = observers_.find(base_event_name);
  if (observer != observers_.end())
    observer->second->OnListenerRemoved(details);
}

void EventRouter::AddLazyEventListener(const std::string& event_name,
                                       const std::string& extension_id) {
  scoped_ptr<EventListener> listener(new EventListener(
      event_name, extension_id, NULL, scoped_ptr<DictionaryValue>()));
  bool is_new = listeners_.AddListener(listener.Pass());

  if (is_new) {
    std::set<std::string> events = GetRegisteredEvents(extension_id);
    bool prefs_is_new = events.insert(event_name).second;
    if (prefs_is_new)
      SetRegisteredEvents(extension_id, events);
  }
}

void EventRouter::RemoveLazyEventListener(const std::string& event_name,
                                          const std::string& extension_id) {
  EventListener listener(event_name, extension_id, NULL,
                         scoped_ptr<DictionaryValue>());
  bool did_exist = listeners_.RemoveListener(&listener);

  if (did_exist) {
    std::set<std::string> events = GetRegisteredEvents(extension_id);
    bool prefs_did_exist = events.erase(event_name) > 0;
    DCHECK(prefs_did_exist);
    SetRegisteredEvents(extension_id, events);
  }
}

void EventRouter::AddFilteredEventListener(const std::string& event_name,
                                           content::RenderProcessHost* process,
                                           const std::string& extension_id,
                                           const base::DictionaryValue& filter,
                                           bool add_lazy_listener) {
  listeners_.AddListener(scoped_ptr<EventListener>(new EventListener(
      event_name, extension_id, process,
      scoped_ptr<DictionaryValue>(filter.DeepCopy()))));

  if (add_lazy_listener) {
    bool added = listeners_.AddListener(scoped_ptr<EventListener>(
        new EventListener(event_name, extension_id, NULL,
        scoped_ptr<DictionaryValue>(filter.DeepCopy()))));

    if (added)
      AddFilterToEvent(event_name, extension_id, &filter);
  }
}

void EventRouter::RemoveFilteredEventListener(
    const std::string& event_name,
    content::RenderProcessHost* process,
    const std::string& extension_id,
    const base::DictionaryValue& filter,
    bool remove_lazy_listener) {
  EventListener listener(event_name, extension_id, process,
                         scoped_ptr<DictionaryValue>(filter.DeepCopy()));

  listeners_.RemoveListener(&listener);

  if (remove_lazy_listener) {
    listener.process = NULL;
    bool removed = listeners_.RemoveListener(&listener);

    if (removed)
      RemoveFilterFromEvent(event_name, extension_id, &filter);
  }
}

bool EventRouter::HasEventListener(const std::string& event_name) {
  return listeners_.HasListenerForEvent(event_name);
}

bool EventRouter::ExtensionHasEventListener(const std::string& extension_id,
                                            const std::string& event_name) {
  return listeners_.HasListenerForExtension(extension_id, event_name);
}

bool EventRouter::HasEventListenerImpl(const ListenerMap& listener_map,
                                       const std::string& extension_id,
                                       const std::string& event_name) {
  ListenerMap::const_iterator it = listener_map.find(event_name);
  if (it == listener_map.end())
    return false;

  const std::set<ListenerProcess>& listeners = it->second;
  if (extension_id.empty())
    return !listeners.empty();

  for (std::set<ListenerProcess>::const_iterator listener = listeners.begin();
       listener != listeners.end(); ++listener) {
    if (listener->extension_id == extension_id)
      return true;
  }
  return false;
}

std::set<std::string> EventRouter::GetRegisteredEvents(
    const std::string& extension_id) {
  std::set<std::string> events;
  const ListValue* events_value = NULL;

  if (!extension_prefs_ ||
      !extension_prefs_->ReadPrefAsList(
           extension_id, kRegisteredEvents, &events_value)) {
    return events;
  }

  for (size_t i = 0; i < events_value->GetSize(); ++i) {
    std::string event;
    if (events_value->GetString(i, &event))
      events.insert(event);
  }
  return events;
}

void EventRouter::SetRegisteredEvents(const std::string& extension_id,
                                      const std::set<std::string>& events) {
  ListValue* events_value = new ListValue;
  for (std::set<std::string>::const_iterator iter = events.begin();
       iter != events.end(); ++iter) {
    events_value->Append(new base::StringValue(*iter));
  }
  extension_prefs_->UpdateExtensionPref(
      extension_id, kRegisteredEvents, events_value);
}

void EventRouter::AddFilterToEvent(const std::string& event_name,
                                   const std::string& extension_id,
                                   const DictionaryValue* filter) {
  ExtensionPrefs::ScopedDictionaryUpdate update(
      extension_prefs_, extension_id, kFilteredEvents);
  DictionaryValue* filtered_events = update.Get();
  if (!filtered_events)
    filtered_events = update.Create();

  ListValue* filter_list = NULL;
  if (!filtered_events->GetList(event_name, &filter_list)) {
    filter_list = new ListValue;
    filtered_events->SetWithoutPathExpansion(event_name, filter_list);
  }

  filter_list->Append(filter->DeepCopy());
}

void EventRouter::RemoveFilterFromEvent(const std::string& event_name,
                                        const std::string& extension_id,
                                        const DictionaryValue* filter) {
  ExtensionPrefs::ScopedDictionaryUpdate update(
      extension_prefs_, extension_id, kFilteredEvents);
  DictionaryValue* filtered_events = update.Get();
  ListValue* filter_list = NULL;
  if (!filtered_events ||
      !filtered_events->GetListWithoutPathExpansion(event_name, &filter_list)) {
    return;
  }

  for (size_t i = 0; i < filter_list->GetSize(); i++) {
    DictionaryValue* filter = NULL;
    CHECK(filter_list->GetDictionary(i, &filter));
    if (filter->Equals(filter)) {
      filter_list->Remove(i, NULL);
      break;
    }
  }
}

const DictionaryValue* EventRouter::GetFilteredEvents(
    const std::string& extension_id) {
  const DictionaryValue* events = NULL;
  extension_prefs_->ReadPrefAsDictionary(
      extension_id, kFilteredEvents, &events);
  return events;
}

void EventRouter::BroadcastEvent(scoped_ptr<Event> event) {
  DispatchEventImpl(std::string(), linked_ptr<Event>(event.release()));
}

void EventRouter::DispatchEventToExtension(const std::string& extension_id,
                                           scoped_ptr<Event> event) {
  DCHECK(!extension_id.empty());
  DispatchEventImpl(extension_id, linked_ptr<Event>(event.release()));
}

void EventRouter::DispatchEventWithLazyListener(const std::string& extension_id,
                                                scoped_ptr<Event> event) {
  DCHECK(!extension_id.empty());
  std::string event_name = event->event_name;
  bool has_listener = ExtensionHasEventListener(extension_id, event_name);
  if (!has_listener)
    AddLazyEventListener(event_name, extension_id);
  DispatchEventToExtension(extension_id, event.Pass());
  if (!has_listener)
    RemoveLazyEventListener(event_name, extension_id);
}

void EventRouter::DispatchEventImpl(const std::string& restrict_to_extension_id,
                                    const linked_ptr<Event>& event) {
  // We don't expect to get events from a completely different browser context.
  DCHECK(!event->restrict_to_browser_context ||
         ExtensionsBrowserClient::Get()->IsSameContext(
             browser_context_, event->restrict_to_browser_context));

  std::set<const EventListener*> listeners(
      listeners_.GetEventListeners(*event));

  std::set<EventDispatchIdentifier> already_dispatched;

  // We dispatch events for lazy background pages first because attempting to do
  // so will cause those that are being suspended to cancel that suspension.
  // As canceling a suspension entails sending an event to the affected
  // background page, and as that event needs to be delivered before we dispatch
  // the event we are dispatching here, we dispatch to the lazy listeners here
  // first.
  for (std::set<const EventListener*>::iterator it = listeners.begin();
       it != listeners.end(); it++) {
    const EventListener* listener = *it;
    if (restrict_to_extension_id.empty() ||
        restrict_to_extension_id == listener->extension_id) {
      if (!listener->process) {
        DispatchLazyEvent(listener->extension_id, event, &already_dispatched);
      }
    }
  }

  for (std::set<const EventListener*>::iterator it = listeners.begin();
       it != listeners.end(); it++) {
    const EventListener* listener = *it;
    if (restrict_to_extension_id.empty() ||
        restrict_to_extension_id == listener->extension_id) {
      if (listener->process) {
        EventDispatchIdentifier dispatch_id(
            listener->process->GetBrowserContext(), listener->extension_id);
        if (!ContainsKey(already_dispatched, dispatch_id)) {
          DispatchEventToProcess(listener->extension_id, listener->process,
              event);
        }
      }
    }
  }
}

void EventRouter::DispatchLazyEvent(
    const std::string& extension_id,
    const linked_ptr<Event>& event,
    std::set<EventDispatchIdentifier>* already_dispatched) {
  // Check both the original and the incognito browser context to see if we
  // should load a lazy bg page to handle the event. The latter case
  // occurs in the case of split-mode extensions.
  const Extension* extension =
      ExtensionRegistry::Get(browser_context_)->enabled_extensions().GetByID(
          extension_id);
  if (!extension)
    return;

  if (MaybeLoadLazyBackgroundPageToDispatchEvent(
          browser_context_, extension, event)) {
    already_dispatched->insert(std::make_pair(browser_context_, extension_id));
  }

  ExtensionsBrowserClient* browser_client = ExtensionsBrowserClient::Get();
  if (browser_client->HasOffTheRecordContext(browser_context_) &&
      IncognitoInfo::IsSplitMode(extension)) {
    BrowserContext* incognito_context =
        browser_client->GetOffTheRecordContext(browser_context_);
    if (MaybeLoadLazyBackgroundPageToDispatchEvent(
            incognito_context, extension, event)) {
      already_dispatched->insert(
          std::make_pair(incognito_context, extension_id));
    }
  }
}

void EventRouter::DispatchEventToProcess(const std::string& extension_id,
                                         content::RenderProcessHost* process,
                                         const linked_ptr<Event>& event) {
  const Extension* extension =
      ExtensionRegistry::Get(browser_context_)->enabled_extensions().GetByID(
          extension_id);

  // The extension could have been removed, but we do not unregister it until
  // the extension process is unloaded.
  if (!extension)
    return;

  BrowserContext* listener_context = process->GetBrowserContext();
  ProcessMap* process_map = ProcessMap::Get(listener_context);
  // If the event is privileged, only send to extension processes. Otherwise,
  // it's OK to send to normal renderers (e.g., for content scripts).
  if (ExtensionAPI::GetSharedInstance()->IsPrivileged(event->event_name) &&
      !process_map->Contains(extension->id(), process->GetID())) {
    return;
  }

  // If the event is restricted to a URL, only dispatch if the extension has
  // permission for it (or if the event originated from itself).
  if (!event->event_url.is_empty() &&
      event->event_url.host() != extension->id() &&
      !extension->GetActivePermissions()->HasEffectiveAccessToURL(
          event->event_url)) {
    return;
  }

  if (!CanDispatchEventToBrowserContext(listener_context, extension, event))
    return;

  if (!event->will_dispatch_callback.is_null()) {
    event->will_dispatch_callback.Run(listener_context, extension,
                                      event->event_args.get());
  }

  DispatchExtensionMessage(process, listener_context, extension->id(),
                           event->event_name, event->event_args.get(),
                           event->user_gesture, event->filter_info);
  IncrementInFlightEvents(listener_context, extension);
}

bool EventRouter::CanDispatchEventToBrowserContext(
    BrowserContext* context,
    const Extension* extension,
    const linked_ptr<Event>& event) {
  // Is this event from a different browser context than the renderer (ie, an
  // incognito tab event sent to a normal process, or vice versa).
  bool cross_incognito = event->restrict_to_browser_context &&
                         context != event->restrict_to_browser_context;
  if (!cross_incognito)
    return true;
  return ExtensionsBrowserClient::Get()->CanExtensionCrossIncognito(
      extension, context);
}

bool EventRouter::MaybeLoadLazyBackgroundPageToDispatchEvent(
    BrowserContext* context,
    const Extension* extension,
    const linked_ptr<Event>& event) {
  if (extension->is_ephemeral() && !event->can_load_ephemeral_apps) {
    // Most events can only be dispatched to ephemeral apps that are already
    // running.
    ProcessManager* pm = ExtensionSystem::Get(context)->process_manager();
    if (!pm->GetBackgroundHostForExtension(extension->id()))
      return false;
  }

  if (!CanDispatchEventToBrowserContext(context, extension, event))
    return false;

  LazyBackgroundTaskQueue* queue = ExtensionSystem::Get(
      context)->lazy_background_task_queue();
  if (queue->ShouldEnqueueTask(context, extension)) {
    linked_ptr<Event> dispatched_event(event);

    // If there's a dispatch callback, call it now (rather than dispatch time)
    // to avoid lifetime issues. Use a separate copy of the event args, so they
    // last until the event is dispatched.
    if (!event->will_dispatch_callback.is_null()) {
      dispatched_event.reset(event->DeepCopy());
      dispatched_event->will_dispatch_callback.Run(
          context, extension, dispatched_event->event_args.get());
      // Ensure we don't call it again at dispatch time.
      dispatched_event->will_dispatch_callback.Reset();
    }

    queue->AddPendingTask(context, extension->id(),
                          base::Bind(&EventRouter::DispatchPendingEvent,
                                     base::Unretained(this), dispatched_event));
    return true;
  }

  return false;
}

// static
void EventRouter::IncrementInFlightEventsOnUI(
    void* browser_context_id,
    const std::string& extension_id) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  BrowserContext* browser_context =
      reinterpret_cast<BrowserContext*>(browser_context_id);
  if (!ExtensionsBrowserClient::Get()->IsValidContext(browser_context))
    return;
  ExtensionSystem* extension_system = ExtensionSystem::Get(browser_context);
  EventRouter* event_router = extension_system->event_router();
  if (!event_router)
    return;
  const Extension* extension =
      ExtensionRegistry::Get(browser_context)->enabled_extensions().GetByID(
          extension_id);
  if (!extension)
    return;
  event_router->IncrementInFlightEvents(browser_context, extension);
}

void EventRouter::IncrementInFlightEvents(BrowserContext* context,
                                          const Extension* extension) {
  // Only increment in-flight events if the lazy background page is active,
  // because that's the only time we'll get an ACK.
  if (BackgroundInfo::HasLazyBackgroundPage(extension)) {
    ProcessManager* pm = ExtensionSystem::Get(context)->process_manager();
    ExtensionHost* host = pm->GetBackgroundHostForExtension(extension->id());
    if (host)
      pm->IncrementLazyKeepaliveCount(extension);
  }
}

void EventRouter::OnEventAck(BrowserContext* context,
                             const std::string& extension_id) {
  ProcessManager* pm = ExtensionSystem::Get(context)->process_manager();
  ExtensionHost* host = pm->GetBackgroundHostForExtension(extension_id);
  // The event ACK is routed to the background host, so this should never be
  // NULL.
  CHECK(host);
  // TODO(mpcomplete): We should never get this message unless
  // HasLazyBackgroundPage is true. Find out why we're getting it anyway.
  if (host->extension() &&
      BackgroundInfo::HasLazyBackgroundPage(host->extension()))
    pm->DecrementLazyKeepaliveCount(host->extension());
}

void EventRouter::DispatchPendingEvent(const linked_ptr<Event>& event,
                                       ExtensionHost* host) {
  if (!host)
    return;

  if (listeners_.HasProcessListener(host->render_process_host(),
                                    host->extension()->id())) {
    DispatchEventToProcess(host->extension()->id(),
                           host->render_process_host(), event);
  }
}

void EventRouter::Observe(int type,
                          const content::NotificationSource& source,
                          const content::NotificationDetails& details) {
  switch (type) {
    case content::NOTIFICATION_RENDERER_PROCESS_TERMINATED:
    case content::NOTIFICATION_RENDERER_PROCESS_CLOSED: {
      content::RenderProcessHost* renderer =
          content::Source<content::RenderProcessHost>(source).ptr();
      // Remove all event listeners associated with this renderer.
      listeners_.RemoveListenersForProcess(renderer);
      break;
    }
    case chrome::NOTIFICATION_EXTENSION_ENABLED: {
      // If the extension has a lazy background page, make sure it gets loaded
      // to register the events the extension is interested in.
      const Extension* extension =
          content::Details<const Extension>(details).ptr();
      if (BackgroundInfo::HasLazyBackgroundPage(extension)) {
        LazyBackgroundTaskQueue* queue = ExtensionSystem::Get(
            browser_context_)->lazy_background_task_queue();
        queue->AddPendingTask(browser_context_, extension->id(),
                              base::Bind(&DoNothing));
      }
      break;
    }
    case chrome::NOTIFICATION_EXTENSION_LOADED: {
      // Add all registered lazy listeners to our cache.
      const Extension* extension =
          content::Details<const Extension>(details).ptr();
      std::set<std::string> registered_events =
          GetRegisteredEvents(extension->id());
      listeners_.LoadUnfilteredLazyListeners(extension->id(),
                                             registered_events);
      const DictionaryValue* filtered_events =
          GetFilteredEvents(extension->id());
      if (filtered_events)
        listeners_.LoadFilteredLazyListeners(extension->id(), *filtered_events);
      break;
    }
    case chrome::NOTIFICATION_EXTENSION_UNLOADED_DEPRECATED: {
      // Remove all registered lazy listeners from our cache.
      UnloadedExtensionInfo* unloaded =
          content::Details<UnloadedExtensionInfo>(details).ptr();
      listeners_.RemoveLazyListenersForExtension(unloaded->extension->id());
      break;
    }
    default:
      NOTREACHED();
      return;
  }
}

Event::Event(const std::string& event_name,
             scoped_ptr<base::ListValue> event_args)
    : event_name(event_name),
      event_args(event_args.Pass()),
      restrict_to_browser_context(NULL),
      user_gesture(EventRouter::USER_GESTURE_UNKNOWN),
      can_load_ephemeral_apps(false) {
  DCHECK(this->event_args.get());
}

Event::Event(const std::string& event_name,
             scoped_ptr<base::ListValue> event_args,
             BrowserContext* restrict_to_browser_context)
    : event_name(event_name),
      event_args(event_args.Pass()),
      restrict_to_browser_context(restrict_to_browser_context),
      user_gesture(EventRouter::USER_GESTURE_UNKNOWN),
      can_load_ephemeral_apps(false) {
  DCHECK(this->event_args.get());
}

Event::Event(const std::string& event_name,
             scoped_ptr<ListValue> event_args,
             BrowserContext* restrict_to_browser_context,
             const GURL& event_url,
             EventRouter::UserGestureState user_gesture,
             const EventFilteringInfo& filter_info)
    : event_name(event_name),
      event_args(event_args.Pass()),
      restrict_to_browser_context(restrict_to_browser_context),
      event_url(event_url),
      user_gesture(user_gesture),
      filter_info(filter_info),
      can_load_ephemeral_apps(false) {
  DCHECK(this->event_args.get());
}

Event::~Event() {}

Event* Event::DeepCopy() {
  Event* copy = new Event(event_name,
                          scoped_ptr<base::ListValue>(event_args->DeepCopy()),
                          restrict_to_browser_context,
                          event_url,
                          user_gesture,
                          filter_info);
  copy->will_dispatch_callback = will_dispatch_callback;
  return copy;
}

EventListenerInfo::EventListenerInfo(const std::string& event_name,
                                     const std::string& extension_id,
                                     content::BrowserContext* browser_context)
    : event_name(event_name),
      extension_id(extension_id),
      browser_context(browser_context) {}

}  // namespace extensions
/* [<][>][^][v][top][bottom][index][help] */
root/extensions/browser/event_router.cc

DEFINITIONS
