Update to Chromium revision 0bfd25d4 (#381305)

- Delete include/cef_runnable.h (issue #1336).
- Build the cef_unittests target using all Chromium headers. Add a
  USING_CHROMIUM_INCLUDES define and libcef_dll_wrapper_unittests
  target to support this. This change avoids compile errors due to
  the divergence of CEF and Chromium base/ header implementations.
  The libcef_dll_wrapper sources must now compile successfully with
  both CEF and Chromium base/ headers (issue #1632).
- The onbeforeunload message specified via JavaScript is no longer
  passed to the client (see http://crbug.com/587940).

libcef/resources/cef_strings.grd

@@ -361,9 +361,6 @@ need to be translated for each locale.-->
       <message name="IDS_PLUGIN_HIDE" desc="The tooltip for hiding a blocked plugin, displayed in the click to play UI.">
         Hide this plugin
       </message>
-      <message name="IDS_PLUGIN_NOT_SUPPORTED" desc="The placeholder text for an unsupported plugin.">
-        This plugin is not supported.
-      </message>
       <if expr="is_macosx">
         <message name="IDS_PLUGIN_BLOCKED" desc="The placeholder text for a blocked plugin.">
           Control-click to play <ph name="PLUGIN_NAME">$1<ex>Flash</ex></ph>.
@@ -404,14 +401,6 @@ need to be translated for each locale.-->
       </if>
       
       <!-- Preferences. -->
-      <!-- The default value for HTTP Accept-Language header. -->
-      <message name="IDS_ACCEPT_LANGUAGES" use_name_for_id="true">
-        en-US,en
-      </message>
-      <!-- The default value for |WebPreference::default_encoding|. -->
-      <message name="IDS_DEFAULT_ENCODING" use_name_for_id="true">
-        windows-1252
-      </message>
       <!-- The default value for |WebPreference::uses_universal_detector|. -->
       <message name="IDS_USES_UNIVERSAL_DETECTOR" use_name_for_id="true">
         false