Add an accessibility API for events raised outside of the web content.

chrome/browser/profile.h

 // Copyright (c) 2010 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.
 
 // This class gathers state related to a single user profile.
 
 #ifndef CHROME_BROWSER_PROFILE_H_
 #define CHROME_BROWSER_PROFILE_H_
 
 #include <set>
@@ skipping 85 matching lines @@
     // The caller plans to call a method that will permanently change some data
     // in the profile, as part of Chrome's implicit data logging. Use this flag
     // when you are about to perform an operation which is incompatible with the
     // off the record mode.
     IMPLICIT_ACCESS
   };
 
   // Value that represents no profile Id.
   static const ProfileId InvalidProfileId;
 
-  Profile() : restored_last_session_(false) {}
+  Profile() : restored_last_session_(false), accessibility_pause_level_(0) {}
   virtual ~Profile() {}
 
   // Profile prefs are registered as soon as the prefs are loaded for the first
   // time.
   static void RegisterUserPrefs(PrefService* prefs);
 
   // Create a new profile given a path.
   static Profile* CreateProfile(const FilePath& path);
 
   // Returns the request context for the "default" profile.  This may be called
@@ skipping 261 matching lines @@
 #endif
 
   // Did the user restore the last session? This is set by SessionRestore.
   void set_restored_last_session(bool restored_last_session) {
     restored_last_session_ = restored_last_session;
   }
   bool restored_last_session() const {
     return restored_last_session_;
   }
 
+  // Stop sending accessibility events until ResumeAccessibilityEvents().
+  // Calls to Pause nest; no events will be sent until the number of
+  // Resume calls matches the number of Pause calls received.
+  void PauseAccessibilityEvents() {
+    accessibility_pause_level_++;
+  }
+
+  void ResumeAccessibilityEvents() {
+    DCHECK(accessibility_pause_level_ > 0);
+    accessibility_pause_level_--;
+  }
+
+  bool ShouldSendAccessibilityEvents() {
+    return 0 == accessibility_pause_level_;
+  }
+
  protected:
   static URLRequestContextGetter* default_request_context_;
 
  private:
   bool restored_last_session_;
+
+  // Accessibility events will only be propagated when the pause
+  // level is zero.  PauseAccessibilityEvents and ResumeAccessibilityEvents
+  // increment and decrement the level, respectively, rather than set it to
+  // true or false, so that calls can be nested.
+  int accessibility_pause_level_;
 };
 
 class OffTheRecordProfileImpl;
 
 // The default profile implementation.
 class ProfileImpl : public Profile,
                     public SpellCheckHostObserver,
                     public NotificationObserver {
  public:
   virtual ~ProfileImpl();
@@ skipping 170 matching lines @@
   scoped_refptr<webkit_database::DatabaseTracker> db_tracker_;
 
 #if defined(OS_CHROMEOS)
   chromeos::Preferences chromeos_preferences_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(ProfileImpl);
 };
 
 #endif  // CHROME_BROWSER_PROFILE_H_