Expose platform thread id on blink::WebThread

mojo/services/html_viewer/webthread_impl.h

Index: mojo/services/html_viewer/webthread_impl.h
diff --git a/mojo/services/html_viewer/webthread_impl.h b/mojo/services/html_viewer/webthread_impl.h
index 3d22d860eb848aa1f9afe354ecf1b8ce6fa72865..93d7aeb3cce2f952245620a6dd72fe7a490bae21 100644
--- a/mojo/services/html_viewer/webthread_impl.h
+++ b/mojo/services/html_viewer/webthread_impl.h
@@ -21,6 +21,7 @@ class WebThreadBase : public blink::WebThread {
   virtual void removeTaskObserver(TaskObserver* observer);
 
   virtual bool isCurrentThread() const = 0;
+  virtual blink::PlatformThreadId threadId() const = 0;
 
  protected:
   WebThreadBase();
@@ -46,6 +47,7 @@ class WebThreadImpl : public WebThreadBase {
   base::MessageLoop* message_loop() const { return thread_->message_loop(); }
 
   virtual bool isCurrentThread() const;
+  virtual blink::PlatformThreadId threadId() const;
 
  private:
   scoped_ptr<base::Thread> thread_;
@@ -65,7 +67,10 @@ class WebThreadImplForMessageLoop : public WebThreadBase {
 
  private:
   virtual bool isCurrentThread() const;
+  virtual blink::PlatformThreadId threadId() const;
+
   scoped_refptr<base::MessageLoopProxy> message_loop_;
+  blink::PlatformThreadId thread_id_;
 };
 
 }  // namespace mojo