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/browser_context_impl.cc

@@ -449,8 +449,8 @@ net::URLRequestContextGetter* CefBrowserContextImpl::CreateRequestContext(
   url_request_getter_ = new CefURLRequestContextGetterImpl(
       settings_,
       GetPrefs(),
-      BrowserThread::UnsafeGetMessageLoopForThread(BrowserThread::IO),
-      BrowserThread::UnsafeGetMessageLoopForThread(BrowserThread::FILE),
+      BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO),
+      BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE),
       protocol_handlers,
       std::move(proxy_config_service),
       std::move(request_interceptors));