Teach the GCM Driver how to decrypt incoming messages.

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 4e17801f33539a8a781a0a444656b10e2f3dd7f6..eed7244e730b400fac06691adc1d0fb2c9865442 100644
--- a/components/gcm_driver/gcm_driver.cc
+++ b/components/gcm_driver/gcm_driver.cc
@@ -13,8 +13,17 @@
 
 namespace gcm {
 
+namespace {
+
 const size_t kMaxSenders = 100;
 
+// TODO(peter): Implement an event for GCMAppHandlers that should be called
+// when decryption of an incoming message has failed.
+void DecryptionFailedCallback(
+    GCMEncryptionProvider::DecryptionFailure reason) {}
+
+}  // namespace
+
 InstanceIDHandler::InstanceIDHandler() {
 }
 
@@ -258,6 +267,20 @@ void GCMDriver::ClearCallbacks() {
   send_callbacks_.clear();
 }
 
+void GCMDriver::DispatchMessage(const std::string& app_id,
+                                const IncomingMessage& message) {
+  if (!encryption_provider_.IsEncryptedMessage(message)) {
+    GetAppHandler(app_id)->OnMessage(app_id, message);
+    return;
+  }
+
+  encryption_provider_.DecryptMessage(
+      app_id, message,
+      base::Bind(&GCMDriver::DispatchMessage,
+                 weak_ptr_factory_.GetWeakPtr(), app_id),
+      base::Bind(&DecryptionFailedCallback));
+}
+
 void GCMDriver::RegisterAfterUnregister(
     const std::string& app_id,
     const std::vector<std::string>& normalized_sender_ids,