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

include/base/cef_lock.h

@@ -113,7 +113,7 @@ class Lock {
 #endif  // NDEBUG
 
   // Platform specific underlying lock implementation.
-  internal::LockImpl lock_;
+  cef_internal::LockImpl lock_;
 
   DISALLOW_COPY_AND_ASSIGN(Lock);
 };