blimp: Cleanup class/struct forward declarations

blimp/engine/browser_tests/blimp_browser_test.h

 // Copyright 2016 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.
 
 #ifndef BLIMP_ENGINE_BROWSER_TESTS_BLIMP_BROWSER_TEST_H_
 #define BLIMP_ENGINE_BROWSER_TESTS_BLIMP_BROWSER_TEST_H_
 
 #include <memory>
 
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/thread_restrictions.h"
 #include "content/public/test/browser_test_base.h"
 
-namespace base {
-class RunLoop;
-}
-
-namespace content {
-class WebContents;
-}
-
 namespace blimp {
 namespace client {
 struct Assignment;
 }  // namespace client
 
 namespace engine {
 class BlimpEngineSession;
 }  // namespace engine
 
 // Base class for tests which require a full instance of the Blimp engine.
@@ skipping 47 matching lines @@
   // require setting up client components, as testing those sometimes requires
   // setting up GL contexts that might block.
   std::unique_ptr<base::ThreadRestrictions::ScopedAllowWait> allow_ui_waits_;
 
   DISALLOW_COPY_AND_ASSIGN(BlimpBrowserTest);
 };
 
 }  // namespace blimp
 
 #endif  // BLIMP_ENGINE_BROWSER_TESTS_BLIMP_BROWSER_TEST_H_