Skeleton GCMAppHandler for Push API

components/gcm_driver/gcm_driver.cc

Index: components/gcm_driver/gcm_driver.cc
diff --git a/components/gcm_driver/gcm_driver.cc b/components/gcm_driver/gcm_driver.cc
index 345fa97dce156622f51083e91f9a98277c68cf9d..d768206bdfd1e923205d2627cce62e4a390132d3 100644
--- a/components/gcm_driver/gcm_driver.cc
+++ b/components/gcm_driver/gcm_driver.cc
@@ -17,6 +17,11 @@ GCMDriver::GCMDriver() {
 GCMDriver::~GCMDriver() {
 }
 
+void GCMDriver::SetLazyLoadAppHandlersClosure(
+    const base::Closure& lazy_load_app_handlers) {
+  lazy_load_app_handlers_ = lazy_load_app_handlers;
+}
+
 void GCMDriver::Register(const std::string& app_id,
                          const std::vector<std::string>& sender_ids,
                          const RegisterCallback& callback) {
@@ -148,7 +153,8 @@ void GCMDriver::AddAppHandler(const std::string& app_id,
                               GCMAppHandler* handler) {
   DCHECK(!app_id.empty());
   DCHECK(handler);
-  DCHECK(app_handlers_.find(app_id) == app_handlers_.end());
+  DCHECK(app_handlers_.find(app_id) == app_handlers_.end() ||
+         app_handlers_[app_id] == handler);
   app_handlers_[app_id] = handler;
 }
 
@@ -158,6 +164,10 @@ void GCMDriver::RemoveAppHandler(const std::string& app_id) {
 }
 
 GCMAppHandler* GCMDriver::GetAppHandler(const std::string& app_id) {
+  if (!lazy_load_app_handlers_.is_null()) {
+    lazy_load_app_handlers_.Run();
+    lazy_load_app_handlers_.Reset();
+  }
   GCMAppHandlerMap::const_iterator iter = app_handlers_.find(app_id);
   return iter == app_handlers_.end() ? &default_app_handler_ : iter->second;
 }