Push API: Validate storage before returning cached subscriptions

components/gcm_driver/gcm_driver_android.cc

Index: components/gcm_driver/gcm_driver_android.cc
diff --git a/components/gcm_driver/gcm_driver_android.cc b/components/gcm_driver/gcm_driver_android.cc
index a512e8248d9a045c091c9c2440ec80577d1b26d8..a0fedd5cf650ea7b0d940baba5007154aff8f961 100644
--- a/components/gcm_driver/gcm_driver_android.cc
+++ b/components/gcm_driver/gcm_driver_android.cc
@@ -13,6 +13,7 @@
 #include "base/android/jni_string.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "jni/GCMDriver_jni.h"
 
 using base::android::AppendJavaStringArrayToStringVector;
@@ -117,6 +118,16 @@ bool GCMDriverAndroid::RegisterJni(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
+void GCMDriverAndroid::ValidateRegistration(
+    const std::string& app_id,
+    const std::vector<std::string>& sender_ids,
+    const std::string& registration_id,
+    const ValidateRegistrationCallback& callback) {
+  // gcm_driver doesn't store registration IDs on Android, so assume it's valid.
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::Bind(callback, true /* is_valid */));
+}
+
 void GCMDriverAndroid::OnSignedIn() {
 }