Enable the embedded L1/EME support in WebView.

content/content_browser.gypi

 # 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.
 
 {
   'dependencies': [
     '../third_party/re2/re2.gyp:re2',
     '../base/base.gyp:base_static',
     '../crypto/crypto.gyp:crypto',
     '../google_apis/google_apis.gyp:google_apis',
@@ skipping 22 matching lines @@
     'port/browser/render_widget_host_view_port.h',
     'port/browser/vibration_provider.h',
     'port/browser/web_contents_view_port.h',
     'public/browser/access_token_store.h',
     'public/browser/android/compositor.h',
     'public/browser/android/compositor_client.h',
     'public/browser/android/content_view_core.h',
     'public/browser/android/content_view_layer_renderer.h',
     'public/browser/android/devtools_auth.h',
     'public/browser/android/download_controller_android.h',
+    'public/browser/android/external_video_surface_container.h',
     'public/browser/android/synchronous_compositor_client.h',
     'public/browser/android/synchronous_compositor.cc',
     'public/browser/android/synchronous_compositor.h',
     'public/browser/browser_accessibility_state.h',
     'public/browser/browser_child_process_host.h',
     'public/browser/browser_child_process_host_delegate.cc',
     'public/browser/browser_child_process_host_delegate.h',
     'public/browser/browser_child_process_host_iterator.cc',
     'public/browser/browser_child_process_host_iterator.h',
     'public/browser/browser_child_process_observer.cc',
@@ skipping 1601 matching lines @@
         '../build/linux/system.gyp:dbus',
         '../dbus/dbus.gyp:dbus',
       ],
     }, {  # OS != "linux" or use_dbus==0
       'sources!': [
         'browser/geolocation/wifi_data_provider_linux.cc',
       ],
     }],
   ],
 }