Split GCMDriver into platform-specific implementations

components/gcm_driver/gcm_driver_unittest.cc

Index: components/gcm_driver/gcm_driver_unittest.cc
diff --git a/components/gcm_driver/gcm_driver_unittest.cc b/components/gcm_driver/gcm_driver_unittest.cc
index 52f6abb2b5e4113781a683439254133da815b1a0..d4694cfb520c2c47ad30818f62e53c15a4ab6818 100644
--- a/components/gcm_driver/gcm_driver_unittest.cc
+++ b/components/gcm_driver/gcm_driver_unittest.cc
@@ -2,7 +2,7 @@
 // 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.h"
+#include "components/gcm_driver/gcm_driver_desktop.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ -190,7 +190,8 @@ void GCMDriverTest::CreateDriver(
     FakeGCMClient::StartMode gcm_client_start_mode) {
   scoped_refptr<net::URLRequestContextGetter> request_context =
       new net::TestURLRequestContextGetter(io_thread_.message_loop_proxy());
-  driver_.reset(new GCMDriver(
+  // TODO(johnme): Need equivalent test coverage of GCMDriverAndroid.
+  driver_.reset(new GCMDriverDesktop(

[jianli, 2014/05/29 07:34:03]

Will this still be built for Android?

[johnme, 2014/05/29 17:40:55]

Great question! It was, but only by accident because I'd misspelled the
'sources!' exclude for gcm_driver_desktop on Android. I've fixed the exclude, so
gcm_driver_desktop is no longer built on Android, but instead I've added
gcm_driver_desktop to 'sources' for gcm_driver_test_support, so it will get
built on Android for tests only.

This means these tests will continue to check that GCMDriverDesktop works on
Android, even though it's not actually used on Android; the alternative would be
to disable the desktop version of these tests on Android. This boils down to: is
it better to test an unsupported configuration, or lose testing for it?

I'm in two minds; happy to change this to disable the tests on Android instead
of adding gcm_driver_desktop to gcm_driver_test_support if you'd prefer.

[jianli, 2014/05/30 06:30:23]

I think we should test GCMDriverAndroid on Android since GCMDriverDesktop is
never used there. If GCMDriverAndroid testing is not ready, we can disable the
tests until they're ready.

[johnme, 2014/05/30 10:26:45]

Done (renamed this file to gcm_driver_desktop_unittest.cc, and disabled it on
Android).

       scoped_ptr<GCMClientFactory>(new FakeGCMClientFactory(
           gcm_client_start_mode,
           base::MessageLoopProxy::current(),