Mojo: Add a "GetType()" to Dispatchers.

mojo/system/simple_dispatcher_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // NOTE(vtl): Some of these tests are inherently flaky (e.g., if run on a
 // heavily-loaded system). Sorry. |kEpsilonMicros| may be increased to increase
 // tolerance and reduce observed flakiness.
 
 #include "mojo/system/simple_dispatcher.h"
 
@@ skipping 39 matching lines @@
   void SetSatisfiableFlags(MojoWaitFlags new_satisfiable_flags) {
     base::AutoLock locker(lock());
 
     if (new_satisfiable_flags == satisfiable_flags_)
       return;
 
     satisfiable_flags_ = new_satisfiable_flags;
     StateChangedNoLock();
   }
 
+  virtual Type GetType() OVERRIDE {
+    return kTypeUnknown;
+  }
+
  private:
   friend class base::RefCountedThreadSafe<MockSimpleDispatcher>;
   virtual ~MockSimpleDispatcher() {}
 
   virtual scoped_refptr<Dispatcher>
       CreateEquivalentDispatcherAndCloseImplNoLock() OVERRIDE {
     scoped_refptr<MockSimpleDispatcher> rv(new MockSimpleDispatcher());
     rv->satisfied_flags_ = satisfied_flags_;
     rv->satisfiable_flags_ = satisfiable_flags_;
     return scoped_refptr<Dispatcher>(rv.get());
@@ skipping 443 matching lines @@
     EXPECT_TRUE(did_wait[i]);
     EXPECT_EQ(MOJO_RESULT_DEADLINE_EXCEEDED, result[i]);
   }
 }
 
 // TODO(vtl): Stress test?
 
 }  // namespace
 }  // namespace system
 }  // namespace mojo