Add various UMA histograms for measuring GCM crypto performance

components/gcm_driver/gcm_driver_desktop.cc

Index: components/gcm_driver/gcm_driver_desktop.cc
diff --git a/components/gcm_driver/gcm_driver_desktop.cc b/components/gcm_driver/gcm_driver_desktop.cc
index 56ee56ccddd1f00bd34bf9a4e1f01cb1706eb39c..5ecc3cc03f7b5fe6fc4f8d4bbe9f59db635d83ad 100644
--- a/components/gcm_driver/gcm_driver_desktop.cc
+++ b/components/gcm_driver/gcm_driver_desktop.cc
@@ -108,7 +108,7 @@ class GCMDriverDesktop::IOWorker : public GCMClient::Delegate {
                    const std::string& scope);
 
   void RecordDecryptionFailure(const std::string& app_id,
-                               GCMEncryptionProvider::DecryptionFailure reason);
+                               GCMEncryptionProvider::DecryptionResult result);
 
   // For testing purpose. Can be called from UI thread. Use with care.
   GCMClient* gcm_client_for_testing() const { return gcm_client_.get(); }
@@ -501,9 +501,9 @@ void GCMDriverDesktop::IOWorker::RemoveHeartbeatInterval(
 
 void GCMDriverDesktop::IOWorker::RecordDecryptionFailure(
     const std::string& app_id,
-    GCMEncryptionProvider::DecryptionFailure reason) {
+    GCMEncryptionProvider::DecryptionResult result) {
   DCHECK(io_thread_->RunsTasksOnCurrentThread());
-  gcm_client_->RecordDecryptionFailure(app_id, reason);
+  gcm_client_->RecordDecryptionFailure(app_id, result);
 }
 
 GCMDriverDesktop::GCMDriverDesktop(
@@ -734,13 +734,13 @@ void GCMDriverDesktop::DoSend(const std::string& app_id,
 
 void GCMDriverDesktop::RecordDecryptionFailure(
     const std::string& app_id,
-    GCMEncryptionProvider::DecryptionFailure reason) {
+    GCMEncryptionProvider::DecryptionResult result) {
   DCHECK(ui_thread_->RunsTasksOnCurrentThread());
   io_thread_->PostTask(
       FROM_HERE,
       base::Bind(&GCMDriverDesktop::IOWorker::RecordDecryptionFailure,
                  base::Unretained(io_worker_.get()),
-                 app_id, reason));
+                 app_id, result));
 }
 
 GCMClient* GCMDriverDesktop::GetGCMClientForTesting() const {