Push API: Validate storage before returning cached subscriptions

components/gcm_driver/gcm_driver_android.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/gcm_driver/gcm_driver_android.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/android/context_utils.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #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;
 using base::android::AttachCurrentThread;
 using base::android::ConvertJavaStringToUTF8;
 using base::android::ConvertUTF8ToJavaString;
 using base::android::JavaByteArrayToByteVector;
 using base::android::JavaParamRef;
 
 namespace gcm {
@@ skipping 84 matching lines @@
                                       message_byte_size);
 
   DispatchMessage(app_id, message);
 }
 
 // static
 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.

[Peter Beverloo, 2017/03/20 23:50:13]

Is there something we could do here long-term, like check with GMScore?

[johnme, 2017/03/30 18:36:38]

No, GMSCore has a cache, but it expires, and there's no way to query it without
registering. More importantly, even if our stored registration is out of sync
with GMSCore's cache, GMSCore will happily forward messages that are sent to our
stored registration - i.e. unlike GCMClientImpl, GMSCore doesn't require that
incoming messages match its stored registrations.

+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::Bind(callback, true /* is_valid */));
+}
+
 void GCMDriverAndroid::OnSignedIn() {
 }
 
 void GCMDriverAndroid::OnSignedOut() {
 }
 
 void GCMDriverAndroid::AddConnectionObserver(GCMConnectionObserver* observer) {
 }
 
 void GCMDriverAndroid::RemoveConnectionObserver(
@@ skipping 130 matching lines @@
   NOTIMPLEMENTED();
 }
 
 void GCMDriverAndroid::RecordDecryptionFailure(
     const std::string& app_id,
     GCMEncryptionProvider::DecryptionResult result) {
   recorder_.RecordDecryptionFailure(app_id, result);
 }
 
 }  // namespace gcm