Move OnCursorChange from CefRenderHandler to CefDisplayHandler

The cursor change can now be handled by the client with both windowed and
off-screen rendering.

Returning true from OnCursorChange will disable the default cursor change
behavior. This is functionally equivalent to the
CefBrowserHost::SetMouseCursorChangeDisabled method, so that method has been
removed.

libcef/browser/chrome/chrome_browser_host_impl.cc

@@ -265,15 +265,6 @@ CefRefPtr<CefRegistration> ChromeBrowserHostImpl::AddDevToolsMessageObserver(
   return nullptr;
 }
 
-void ChromeBrowserHostImpl::SetMouseCursorChangeDisabled(bool disabled) {
-  NOTIMPLEMENTED();
-}
-
-bool ChromeBrowserHostImpl::IsMouseCursorChangeDisabled() {
-  NOTIMPLEMENTED();
-  return false;
-}
-
 bool ChromeBrowserHostImpl::IsWindowRenderingDisabled() {
   return false;
 }