AddHistogramCallback  823 chrome/browser/chromeos/accessibility/accessibility_manager.cc     content::BrowserAccessibilityState::GetInstance()->AddHistogramCallback(
AddHistogramCallback   48 content/browser/accessibility/browser_accessibility_state_impl.h   virtual void AddHistogramCallback(base::Closure callback) OVERRIDE;
AddHistogramCallback   46 content/public/browser/browser_accessibility_state.h   virtual void AddHistogramCallback(base::Closure callback) = 0;