[TimeZoneMonitor] Decouple renderer side impl from content to blink.

third_party/WebKit/public/platform/Platform.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 123 matching lines @@
   typedef HANDLE FileHandle;
 #else
   typedef int FileHandle;
 #endif
 
   // Initialize platform and wtf. If you need to initialize the entire Blink,
   // you should use blink::initialize.
   static void initialize(Platform*);
   static void shutdown();
   static Platform* current();
+  // Used to get whether message loop is ready for current thread, to help
+  // blink::initialize() determining whether can initialize mojo stuff or not.
+  // TODO(leonhsl): http://crbug.com/660274 Remove this public API by ensuring
+  // a message loop before calling blink::initialize().
+  static bool isMessageLoopReady();

[kinuko, 2016/11/08 03:22:56]

(Putting aside the need of this method that seems to have discussed so long)

do we need this method to be exposed at Platform?  This seems to be only used in
Source/modules/ModulesInitializer.cpp or my text search is broken.  Could this
be placed, say, in platform/mojo/MojoHelper.h?  (It's orthogonal to mojo but we
wouldn't want to make it stick around for general use either)

[leonhsl(Using Gerrit), 2016/11/08 08:20:39]

Yes the only user is Source/modules/ModulesInitializer.cpp.
I'm sure ModulesInitializer.cpp is able to call Platform public APIs so I put
the API here.

And, I tried to put isMessageLoopReady() definition into
platform/mojo/MojoHelper.h, but got build error as bellow. Any ideas? Thanks.

"
In file included from
../../third_party/WebKit/Source/modules/imagecapture/ImageCapture.cpp:18:
../../third_party/WebKit/Source/platform/mojo/MojoHelper.h:36:15: error: unused
function 'isMessageLoopReady' [-Werror,-Wunused-function]
  static bool isMessageLoopReady() {
"

 
   // Used to switch the current platform only for testing.
   static void setCurrentPlatformForTesting(Platform*);
 
   // May return null.
   virtual WebCookieJar* cookieJar() { return nullptr; }
 
   // Must return non-null.
   virtual WebClipboard* clipboard() { return nullptr; }
 
@@ skipping 525 matching lines @@
  protected:
   Platform();
   virtual ~Platform() {}
 
   WebThread* m_mainThread;
 };
 
 }  // namespace blink
 
 #endif