Keep the GCM data intact when the user signs out of the profile

components/gcm_driver/fake_gcm_client.cc

Index: components/gcm_driver/fake_gcm_client.cc
diff --git a/components/gcm_driver/fake_gcm_client.cc b/components/gcm_driver/fake_gcm_client.cc
index 6ad3816e1810e87fd40d459e2225d9288ba390ce..605122249165ac171af3e5e52a8bb201073e7235 100644
--- a/components/gcm_driver/fake_gcm_client.cc
+++ b/components/gcm_driver/fake_gcm_client.cc
@@ -8,6 +8,7 @@
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/sequenced_task_runner.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/sys_byteorder.h"
 #include "base/time/time.h"
 #include "google_apis/gcm/base/encryptor.h"
@@ -21,6 +22,7 @@ FakeGCMClient::FakeGCMClient(
     const scoped_refptr<base::SequencedTaskRunner>& ui_thread,
     const scoped_refptr<base::SequencedTaskRunner>& io_thread)
     : delegate_(NULL),
+      sequence_id_(0),
       status_(UNINITIALIZED),
       start_mode_(start_mode),
       ui_thread_(ui_thread),
@@ -68,6 +70,7 @@ void FakeGCMClient::Stop() {
 void FakeGCMClient::CheckOut() {
   DCHECK(io_thread_->RunsTasksOnCurrentThread());
   status_ = CHECKED_OUT;
+  sequence_id_++;
 }
 
 void FakeGCMClient::Register(const std::string& app_id,
@@ -157,9 +160,8 @@ void FakeGCMClient::DeleteMessages(const std::string& app_id) {
                  app_id));
 }
 
-// static
 std::string FakeGCMClient::GetRegistrationIdFromSenderIds(
-    const std::vector<std::string>& sender_ids) {
+    const std::vector<std::string>& sender_ids) const {
   // GCMService normalizes the sender IDs by making them sorted.
   std::vector<std::string> normalized_sender_ids = sender_ids;
   std::sort(normalized_sender_ids.begin(), normalized_sender_ids.end());
@@ -175,6 +177,7 @@ std::string FakeGCMClient::GetRegistrationIdFromSenderIds(
         registration_id += ",";
       registration_id += normalized_sender_ids[i];
     }
+    registration_id += base::IntToString(sequence_id_);
   }
   return registration_id;
 }