Make chrome.instanceID only available on dev and canary.

chrome/browser/services/gcm/instance_id/instance_id_profile_service.cc

 // Copyright (c) 2015 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 "chrome/browser/services/gcm/instance_id/instance_id_profile_service.h"
 
 #include "base/logging.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/services/gcm/gcm_profile_service.h"
 #include "chrome/browser/services/gcm/gcm_profile_service_factory.h"
 #include "chrome/common/chrome_version_info.h"
 #include "components/gcm_driver/instance_id/instance_id_driver.h"
 
 namespace instance_id {
 
 // static
 bool InstanceIDProfileService::IsInstanceIDEnabled(Profile* profile) {
   // Instance ID depends on GCM which has to been enabled.
   if (!gcm::GCMProfileService::IsGCMEnabled(profile))
     return false;
 
-  // Enabled for trunk build.
+  // Enabled only for trunk/canary/dev builds.
   chrome::VersionInfo::Channel channel = chrome::VersionInfo::GetChannel();
-  if (channel == chrome::VersionInfo::CHANNEL_UNKNOWN)
-    return true;
+  if (channel == chrome::VersionInfo::CHANNEL_BETA ||
+      channel == chrome::VersionInfo::CHANNEL_STABLE) {

[Nico, 2015/05/17 01:19:26]

What's the motivation for this? We try to not make features available based on
the channel. Can you use a command-line flag (and optionally an about:flags
entry) instead?

+    return false;
+  }
 
   return InstanceIDDriver::IsInstanceIDEnabled();
 }
 
 InstanceIDProfileService::InstanceIDProfileService(Profile* profile) {
   DCHECK(!profile->IsOffTheRecord());
 
   driver_.reset(new InstanceIDDriver(
       gcm::GCMProfileServiceFactory::GetForProfile(profile)->driver()));
 }
 
 InstanceIDProfileService::~InstanceIDProfileService() {
 }
 
 }  // namespace instance_id