Componentizes external_video_surface to reduce webview/Cast duplication.

components/external_video_surface.gypi

+# Copyright 2015 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.
+
+{
+  'variables': {
+    'chromium_code': 1
+  },
+  'targets': [
+    {
+      'target_name': 'external_video_surface',
+      'type': 'static_library',
+      'dependencies': [
+        '../base/base.gyp:base',
+        '../content/content.gyp:content_browser',
+        'external_video_surface_jni_headers',
+      ],
+      'sources': [
+        'external_video_surface/browser/android/external_video_surface_container_impl.cc',
+        'external_video_surface/browser/android/external_video_surface_container_impl.h',
+        'external_video_surface/component_jni_registrar.cc',
+        'external_video_surface/component_jni_registrar.h',
+      ],
+    },
+    {
+      'target_name': 'external_video_surface_java',
+      'type': 'none',
+      'dependencies': [
+        '../base/base.gyp:base',
+        '../content/content.gyp:content_java',
+      ],
+      'variables': {
+        'java_in_dir': 'external_video_surface/android/java',
+      },
+      'includes': [ '../build/java.gypi' ],
+    },
+    {
+      'target_name': 'external_video_surface_jni_headers',
+      'type': 'none',
+      'sources': [
+        'external_video_surface/android/java/src/org/chromium/components/external_video_surface/ExternalVideoSurfaceContainer.java',
+      ],
+      'variables': {
+        'jni_gen_package': 'external_video_surface',
+      },
+      'includes': [ '../build/jni_generator.gypi' ],
+    },
+  ],
+}