Move renderer plugin code into a new component.

components/plugins.gypi

+# Copyright (c) 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.
+
+{
+  'targets': [
+    {
+      'target_name': 'plugins_renderer',
+      'type': 'static_library',
+      'dependencies': [
+        '../skia/skia.gyp:skia',
+        '../third_party/re2/re2.gyp:re2',
+        '../third_party/WebKit/public/blink.gyp:blink',
+      ],
+      'include_dirs': [
+        '..',
+      ],
+      'sources': [
+        'plugins/renderer/plugin_placeholder.cc',
+        'plugins/renderer/plugin_placeholder.h',
+        'plugins/renderer/plugin_uma.cc',
+        'plugins/renderer/plugin_uma.h',
+        'plugins/renderer/webview_plugin.cc',
+        'plugins/renderer/webview_plugin.h',
+      ],
+      'conditions' : [
+        ['OS=="android"', {
+          'defines': [
+             'ENABLE_MOBILE_YOUTUBE_PLUGIN',
+          ],
+        }],
+      ],
+    },
+  ]
+}