Don't use Compositor::Initialize for Aura Android

chrome/browser/chrome_browser_main_android.cc

 // Copyright (c) 2012 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/chrome_browser_main_android.h"
 
 #include "base/android/build_info.h"
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
@@ skipping 82 matching lines @@
       base::Bind(&DeleteFileTask, bookmark_image_file_path),
       base::TimeDelta::FromMinutes(1));
 }
 
 void ChromeBrowserMainPartsAndroid::PreEarlyInitialization() {
   TRACE_EVENT0("startup",
     "ChromeBrowserMainPartsAndroid::PreEarlyInitialization")
   net::NetworkChangeNotifier::SetFactory(
       new net::NetworkChangeNotifierFactoryAndroid());
 
+#if !defined(USE_AURA)
   content::Compositor::Initialize();

[sky, 2015/11/30 23:56:20]

That this code was compiling tells me you still have the Initialize function. If
you're going to ifdef calling it, shouldn't you also ifdef the function
implementation?
Personally I would be inclined to leave this code as is and have an empty
implementation for android.

[bshe, 2015/12/01 02:24:16]

ifdefed the function declaration.

Sorry. I probably did a bad job explaining this CL. My understanding is that we
will get a compile error for Aura Android without this ifdef. The implementation
for this function is not included in Aura Android. We don't expect to use
Android's compositor. So we use ifdef here instead of implement it for Aura
Android.

+#endif
 
   // Chrome on Android does not use default MessageLoop. It has its own
   // Android specific MessageLoop.
   DCHECK(!main_message_loop_.get());
 
   // Create and start the MessageLoop.
   // This is a critical point in the startup process.
   {
     TRACE_EVENT0("startup",
       "ChromeBrowserMainPartsAndroid::PreEarlyInitialization:CreateUiMsgLoop");
@@ skipping 19 matching lines @@
   ChromeBrowserMainParts::PostBrowserStart();
 
   content::BrowserThread::GetBlockingPool()->PostDelayedTask(FROM_HERE,
       base::Bind(&SeccompSupportDetector::StartDetection),
       base::TimeDelta::FromMinutes(1));
 }
 
 void ChromeBrowserMainPartsAndroid::ShowMissingLocaleMessageBox() {
   NOTREACHED();
 }