[GCM] Observe the event listener adding such that GCM can be started

chrome/browser/extensions/api/gcm/gcm_api.cc

 // Copyright 2013 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 "chrome/browser/extensions/api/gcm/gcm_api.h"
 
 #include <algorithm>
 #include <map>
 #include <vector>
 
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/services/gcm/gcm_profile_service.h"
 #include "chrome/browser/services/gcm/gcm_profile_service_factory.h"
 #include "chrome/common/extensions/api/gcm.h"
-#include "extensions/browser/event_router.h"
 #include "extensions/browser/extension_system.h"
 #include "extensions/common/extension.h"
 
 namespace {
 
 const size_t kMaximumMessageSize = 4096;  // in bytes.
 const char kCollapseKey[] = "collapse_key";
 const char kGoogDotRestrictedPrefix[] = "goog.";
 const char kGoogleRestrictedPrefix[] = "google";
 
@@ skipping 143 matching lines @@
     if (!IsMessageKeyValid(iter->first) ||
         kMaximumMessageSize < iter->first.size() ||
         kMaximumMessageSize < iter->second.size() ||
         kMaximumMessageSize < total_size)
       return false;
   }
 
   return total_size != 0;
 }
 
-GcmJsEventRouter::GcmJsEventRouter(Profile* profile) : profile_(profile) {}
+GcmJsEventRouter::GcmJsEventRouter(Profile* profile) : profile_(profile) {
+  if (ExtensionSystem::Get(profile_)->event_router()) {
+    ExtensionSystem::Get(profile_)->event_router()->RegisterObserver(
+        this, api::gcm::OnMessage::kEventName);
+    ExtensionSystem::Get(profile_)->event_router()->RegisterObserver(
+        this, api::gcm::OnMessagesDeleted::kEventName);
+    ExtensionSystem::Get(profile_)->event_router()->RegisterObserver(
+        this, api::gcm::OnSendError::kEventName);
+  }
+}
 
-GcmJsEventRouter::~GcmJsEventRouter() {}
+GcmJsEventRouter::~GcmJsEventRouter() {
+  if (ExtensionSystem::Get(profile_)->event_router())
+    ExtensionSystem::Get(profile_)->event_router()->UnregisterObserver(this);
+}
 
 void GcmJsEventRouter::OnMessage(
     const std::string& app_id,
     const gcm::GCMClient::IncomingMessage& message) {
   api::gcm::OnMessage::Message message_arg;
   message_arg.data.additional_properties = message.data;
   if (!message.collapse_key.empty())
     message_arg.collapse_key.reset(new std::string(message.collapse_key));
 
   scoped_ptr<Event> event(new Event(
@@ skipping 21 matching lines @@
   error.error_message = GcmResultToError(result);
 
   scoped_ptr<Event> event(new Event(
       api::gcm::OnSendError::kEventName,
       api::gcm::OnSendError::Create(error).Pass(),
       profile_));
   ExtensionSystem::Get(profile_)->event_router()->DispatchEventToExtension(
       app_id, event.Pass());
 }
 
+void GcmJsEventRouter::OnListenerAdded(const EventListenerInfo& details) {
+  if (gcm::GCMProfileService::GetGCMEnabledState(profile_) ==
+      gcm::GCMProfileService::ALWAYS_DISABLED) {
+    return;
+  }
+  gcm::GCMProfileServiceFactory::GetForProfile(profile_)->Start();
+}
+
 }  // namespace extensions