Don't share Push API message payloads unless explicitly enabled.

chrome/browser/services/gcm/push_messaging_browsertest.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 <map>
 #include <string>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 98 matching lines @@
 
 class PushMessagingBrowserTest : public InProcessBrowserTest {
  public:
   PushMessagingBrowserTest() : gcm_service_(nullptr) {}
   ~PushMessagingBrowserTest() override {}
 
   // InProcessBrowserTest:
   void SetUpCommandLine(base::CommandLine* command_line) override {
     command_line->AppendSwitch(
         switches::kEnableExperimentalWebPlatformFeatures);
+    command_line->AppendSwitch(
+        switches::kEnablePushMessagePayload);
 
     InProcessBrowserTest::SetUpCommandLine(command_line);
   }
 
   // InProcessBrowserTest:
   void SetUp() override {
     https_server_.reset(new net::SpawnedTestServer(
         net::SpawnedTestServer::TYPE_HTTPS,
         net::BaseTestServer::SSLOptions(
             net::BaseTestServer::SSLOptions::CERT_OK),
@@ skipping 465 matching lines @@
 
   gcm_service()->AddExpectedUnregisterResponse(GCMClient::UNKNOWN_ERROR);
 
   ASSERT_TRUE(RunScript("unregister()", &script_result));
   EXPECT_EQ("unregister error: "
             "UnknownError: Unexpected error while trying to unregister from the"
             " push server.", script_result);
 }
 
 }  // namespace gcm