Convert ProtocolHandlerRegistry to be a ProfileKeyedService.

base/message_loop.h

Index: base/message_loop.h
diff --git a/base/message_loop.h b/base/message_loop.h
index eeba6bb26f9c3d31ada0e6167b1018677777a94d..0812c0fcc2902543ee4a01dfaa919af5971ce259 100644
--- a/base/message_loop.h
+++ b/base/message_loop.h
@@ -258,6 +258,10 @@ class BASE_EXPORT MessageLoop : public base::MessagePump::Delegate {
   // arbitrary MessageLoop to QuitWhenIdle.
   static base::Closure QuitWhenIdleClosure();
 
+  // Returns true if this loop is |type|. This allows subclasses (especially
+  // those in tests) to specialize how they are identified.
+  virtual bool IsType(Type type) const;
+
   // Returns the type passed to the constructor.
   Type type() const { return type_; }