Reland: Add GCMChannelStatusSyncer to schedule requests and enable/disable GCM

components/gcm_driver/gcm_channel_status_request.cc

Index: components/gcm_driver/gcm_channel_status_request.cc
diff --git a/components/gcm_driver/gcm_channel_status_request.cc b/components/gcm_driver/gcm_channel_status_request.cc
index a027a7f17a9d3d4f4726665c581482bbd30c3f24..e996a543822b8a014e3ea1c42ba53e0f9f98f93a 100644
--- a/components/gcm_driver/gcm_channel_status_request.cc
+++ b/components/gcm_driver/gcm_channel_status_request.cc
@@ -41,12 +41,12 @@ GCMChannelStatusRequest::~GCMChannelStatusRequest() {
 }
 
 // static
-int GCMChannelStatusRequest::default_poll_interval_seconds_for_testing() {
+int GCMChannelStatusRequest::default_poll_interval_seconds() {
   return kDefaultPollIntervalSeconds;
 }
 
 // static
-int GCMChannelStatusRequest::min_poll_interval_seconds_for_testing() {
+int GCMChannelStatusRequest::min_poll_interval_seconds() {
   return kMinPollIntervalSeconds;
 }