Remove BrowserPlugin tests (only one test remaining with existing coverage)

content/renderer/browser_plugin/browser_plugin_manager_impl.h

-// Copyright (c) 2012 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 CONTENT_RENDERER_BROWSER_PLUGIN_BROWSER_PLUGIN_MANAGER_IMPL_H_
-#define CONTENT_RENDERER_BROWSER_PLUGIN_BROWSER_PLUGIN_MANAGER_IMPL_H_
-
-#include <map>
-
-#include "content/renderer/browser_plugin/browser_plugin_manager.h"
-#include "ui/gfx/size.h"
-
-namespace gfx {
-class Point;
-}
-
-namespace content {
-
-class BrowserPluginManagerImpl : public BrowserPluginManager {
- public:
-  explicit BrowserPluginManagerImpl(RenderViewImpl* render_view);
-
-  // BrowserPluginManager implementation.
-  virtual BrowserPlugin* CreateBrowserPlugin(
-      RenderViewImpl* render_view,
-      blink::WebFrame* frame,
-      scoped_ptr<BrowserPluginDelegate> delegate) OVERRIDE;
-
-  // IPC::Sender implementation.
-  virtual bool Send(IPC::Message* msg) OVERRIDE;
-
-  // RenderViewObserver override. Call on render thread.
-  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
-  virtual void DidCommitCompositorFrame() OVERRIDE;
-
- private:
-  virtual ~BrowserPluginManagerImpl();
-
-  DISALLOW_COPY_AND_ASSIGN(BrowserPluginManagerImpl);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_RENDERER_BROWSER_PLUGIN_BROWSER_PLUGIN_MANAGER_IMPL_H_