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/browser/component_updater/cef_component_updater_configurator.cc

@@ -112,6 +112,7 @@ class CefConfigurator : public Configurator {
       CreateOutOfProcessPatcher() const override;
   bool DeltasEnabled() const override;
   bool UseBackgroundDownloader() const override;
+  bool UseCupSigning() const override;
   scoped_refptr<base::SequencedTaskRunner> GetSequencedTaskRunner()
       const override;
 
@@ -264,6 +265,10 @@ bool CefConfigurator::UseBackgroundDownloader() const {
   return background_downloads_enabled_;
 }
 
+bool CefConfigurator::UseCupSigning() const {
+  return true;
+}
+
 scoped_refptr<base::SequencedTaskRunner>
 CefConfigurator::GetSequencedTaskRunner() const {
   return content::BrowserThread::GetBlockingPool()