Add WebScheduler implementation to HTMLViewer

mojo/services/html_viewer/blink_platform_impl.cc

Index: mojo/services/html_viewer/blink_platform_impl.cc
diff --git a/mojo/services/html_viewer/blink_platform_impl.cc b/mojo/services/html_viewer/blink_platform_impl.cc
index 441ca0c182e643a3530d9dcb85f458c76030796b..e94e70ac22c772e4e9844fe6e2052bddf0e5edf9 100644
--- a/mojo/services/html_viewer/blink_platform_impl.cc
+++ b/mojo/services/html_viewer/blink_platform_impl.cc
@@ -51,7 +51,8 @@ BlinkPlatformImpl::BlinkPlatformImpl()
       shared_timer_fire_time_(0.0),
       shared_timer_fire_time_was_set_while_suspended_(false),
       shared_timer_suspended_(0),
-      current_thread_slot_(&DestroyCurrentThread) {
+      current_thread_slot_(&DestroyCurrentThread),
+      scheduler_(main_loop_->message_loop_proxy()) {
 }
 
 BlinkPlatformImpl::~BlinkPlatformImpl() {
@@ -65,6 +66,10 @@ blink::WebThemeEngine* BlinkPlatformImpl::themeEngine() {
   return &theme_engine_;
 }
 
+blink::WebScheduler* BlinkPlatformImpl::scheduler() {
+  return &scheduler_;
+}
+
 blink::WebString BlinkPlatformImpl::defaultLocale() {
   return blink::WebString::fromUTF8("en-US");
 }