Update to Chromium revision 8cb76f56 (#307671)

- Linux/Mac: Load V8 initial snapshot from external bin files (see http://crbug.com/421063).
- Windows: 8.1 SDK is now required (issue #1470).
- Remove CefDOMDocument::GetSelectionStartNode and GetSelectionEndNode methods(see https://codereview.chromium.org/763043004).
- Rename internal namespace used in base headers to avoid linker conflicts with cef_sandbox.lib.

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@1956 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

libcef/browser/browser_host_impl.cc

@@ -2256,7 +2256,8 @@ void CefBrowserHostImpl::DidNavigateMainFramePostCommit(
 }
 
 content::JavaScriptDialogManager*
-    CefBrowserHostImpl::GetJavaScriptDialogManager() {
+    CefBrowserHostImpl::GetJavaScriptDialogManager(
+        content::WebContents* source) {
   if (!dialog_manager_.get())
     dialog_manager_.reset(new CefJavaScriptDialogManager(this));
   return dialog_manager_.get();