Remove unused includes of plugin_list.h. Also remove unused ContentClient and webkit_support method…

webkit/support/test_webplugin_page_delegate.cc

-// 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.
-
-#include "webkit/support/test_webplugin_page_delegate.h"
-
-#include "third_party/WebKit/public/platform/Platform.h"
-#include "third_party/WebKit/public/web/WebKit.h"
-
-namespace webkit_support {
-
-webkit::npapi::WebPluginDelegate*
-TestWebPluginPageDelegate::CreatePluginDelegate(
-    const base::FilePath& file_path,
-    const std::string& mime_type) {
-  webkit::npapi::WebPluginDelegateImpl* delegate =
-      webkit::npapi::WebPluginDelegateImpl::Create(file_path, mime_type);
-#if defined(OS_MACOSX) && !defined(USE_AURA)
-  if (delegate)
-    delegate->SetContainerVisibility(true);
-#endif
-  return delegate;
-}
-
-WebKit::WebPlugin* TestWebPluginPageDelegate::CreatePluginReplacement(
-    const base::FilePath& file_path) {
-  return NULL;
-}
-
-WebKit::WebCookieJar* TestWebPluginPageDelegate::GetCookieJar() {
-  return WebKit::Platform::current()->cookieJar();
-}
-
-}  // namespace webkit_support
-