[Reland] Make canceling Timers fast.

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 d2f948968cd77482e0233576e9277aaee46ebd9a..fa2705bc49e088362cb6c46bc38348368cf6ccf8 100644
--- a/third_party/WebKit/public/platform/WebTaskRunner.h
+++ b/third_party/WebKit/public/platform/WebTaskRunner.h
@@ -40,6 +40,10 @@ public:
     // Takes ownership of |Task|. Can be called from any thread.
     virtual void postDelayedTask(const WebTraceLocation&, Task*, double delayMs) = 0;
 
+    // Schedule a task to be run after |delayMs| on the the associated WebThread.
+    // Can be called from any thread.
+    virtual void postDelayedTask(const WebTraceLocation&, const base::Closure&, double delayMs) = 0;
+
     // Returns a clone of the WebTaskRunner.
     virtual std::unique_ptr<WebTaskRunner> clone() = 0;