Fix OSR surface sizing on browser resize (fixes issue #2733).

This includes the following changes:
- Update usage of surface IDs to match the Aura implementation from the
  RWHVAura/Window classes.
- Batch CefBrowserHost::WasResized calls to avoid excessive/unnecessary calls
  to SynchronizeVisualProperties.
- Cache the results of CefRenderHandler::GetViewRect after resize and make
  RWHVOSR::GetViewBounds the source of truth for all size calculations.
- Fix bounds calculations in CefVideoConsumerOSR with GPU enabled.

Known issues:
- The size passed to OnPaint may be off by 1 pixel in cases where the device
  scale factor is not 1 and does not divide evenly into the pixel size. This is
  due to the inexact conversion from integer pixel size to integer logical size
  for GetViewRect.

libcef/browser/browser_host_impl.cc

@@ -1079,7 +1079,7 @@ void CefBrowserHostImpl::WasResized() {
   if (!web_contents() || !platform_delegate_)
     return;
 
-  platform_delegate_->SynchronizeVisualProperties();
+  platform_delegate_->WasResized();
 }
 
 void CefBrowserHostImpl::WasHidden(bool hidden) {