Implement InstanceIDAndroid using InstanceIDWithSubtype.java

components/gcm_driver/instance_id/instance_id_driver.cc

Index: components/gcm_driver/instance_id/instance_id_driver.cc
diff --git a/components/gcm_driver/instance_id/instance_id_driver.cc b/components/gcm_driver/instance_id/instance_id_driver.cc
index 374be2244a51c26945eddc7c0807fe702c45b07d..937d77b4bb416cadd1d672bb16d9feffc21bfb78 100644
--- a/components/gcm_driver/instance_id/instance_id_driver.cc
+++ b/components/gcm_driver/instance_id/instance_id_driver.cc
@@ -12,22 +12,15 @@
 namespace instance_id {
 
 namespace {
-#if !defined(OS_ANDROID)
 const char kInstanceIDFieldTrialName[] = "InstanceID";
 const char kInstanceIDFieldTrialEnabledGroupName[] = "Enabled";
-#endif    // !defined(OS_ANDROID)
 }  // namespace
 
 // static
 bool InstanceIDDriver::IsInstanceIDEnabled() {
-#if defined(OS_ANDROID)
-  // Not implemented yet.
-  return false;
-#else
   std::string group_name =
       base::FieldTrialList::FindFullName(kInstanceIDFieldTrialName);
   return group_name == kInstanceIDFieldTrialEnabledGroupName;
-#endif    // defined(OS_ANDROID)
 }
 
 InstanceIDDriver::InstanceIDDriver(gcm::GCMDriver* gcm_driver)