Use the scheduling mechanism provided by the platform

Source/web/WebKit.cpp

Index: Source/web/WebKit.cpp
diff --git a/Source/web/WebKit.cpp b/Source/web/WebKit.cpp
index a6d8754f039f03651bf6d9c7c4ae1cc86cba318e..1fcf4c7d308d097790371ea496447a3dcdd50caa 100644
--- a/Source/web/WebKit.cpp
+++ b/Source/web/WebKit.cpp
@@ -50,9 +50,9 @@
 #include "platform/heap/Heap.h"
 #include "platform/heap/glue/MessageLoopInterruptor.h"
 #include "platform/heap/glue/PendingGCRunner.h"
-#include "platform/scheduler/Scheduler.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebPrerenderingSupport.h"
+#include "public/platform/WebScheduler.h"
 #include "public/platform/WebThread.h"
 #include "web/IndexedDBClientImpl.h"
 #include "web/WebMediaPlayerClientImpl.h"
@@ -148,7 +148,6 @@ void initializeWithoutV8(Platform* platform)
     WTF::initialize(currentTimeFunction, monotonicallyIncreasingTimeFunction);
     WTF::initializeMainThread(callOnMainThreadFunction);
     Heap::init();
-    Scheduler::initializeOnMainThread();
 
     ThreadState::attachMainThread();
     // currentThread will always be non-null in production, but can be null in Chromium unit tests.
@@ -226,7 +225,8 @@ void shutdownWithoutV8()
 {
     ASSERT(!s_endOfTaskRunner);
     CoreInitializer::shutdown();
-    Scheduler::shutdown();
+    if (WebScheduler* scheduler = Platform::current()->scheduler())

[eseidel, 2014/10/21 16:11:02]

Does this need to be before WTF and Heap?  Is this just draining the event
queue?

[Sami, 2014/10/21 18:49:34]

Yes, it needs to be right between CoreInitializer::shutdown() (which can still
post new tasks, e.g., from JS) and Heap::shutdown() (which makes any posted
tasks invalid -- we can't even delete them safely after that point). Shutdown
deletes all the pending tasks we have queued up but doesn't run them.

+        scheduler->shutdown();
     Heap::shutdown();
     WTF::shutdown();
     Platform::shutdown();