Add thread affinity and ASSERT() for same-thread restriction to WTF::Function

third_party/WebKit/public/platform/WebTaskRunner.h

Index: third_party/WebKit/public/platform/WebTaskRunner.h
diff --git a/third_party/WebKit/public/platform/WebTaskRunner.h b/third_party/WebKit/public/platform/WebTaskRunner.h
index 5763817588e9e9bd9082418e5c2764b648b0d54b..10b1583749104a3ed605086bf95a5bde7459af5f 100644
--- a/third_party/WebKit/public/platform/WebTaskRunner.h
+++ b/third_party/WebKit/public/platform/WebTaskRunner.h
@@ -57,12 +57,14 @@ public:
 
 #ifdef INSIDE_BLINK
     // Helpers for posting bound functions as tasks.
-    typedef Function<void()> ClosureTask;
 
-    void postTask(const WebTraceLocation&, PassOwnPtr<ClosureTask>);
-    // TODO(alexclarke): Remove this when possible.
-    void postDelayedTask(const WebTraceLocation&, PassOwnPtr<ClosureTask>, long long delayMs);
-    void postDelayedTask(const WebTraceLocation&, PassOwnPtr<ClosureTask>, double delayMs);
+    // For cross-thread posting. Can be called from any thread.
+    void postTask(const WebTraceLocation&, PassOwnPtr<CrossThreadClosure>);
+    void postDelayedTask(const WebTraceLocation&, PassOwnPtr<CrossThreadClosure>, long long delayMs);
+
+    // For same-thread posting. Must be called from the associated WebThread.
+    void postTask(const WebTraceLocation&, PassOwnPtr<SameThreadClosure>);
+    void postDelayedTask(const WebTraceLocation&, PassOwnPtr<SameThreadClosure>, long long delayMs);
 
     PassOwnPtr<WebTaskRunner> adoptClone()
     {