mojo: Fix html_viewer build break from https://codereview.chromium.org/1115443002

TBR=sky@chromium.org

Review URL: https://codereview.chromium.org/1112603003

Cr-Commit-Position: refs/heads/master@{#327347}

components/html_viewer/blink_platform_impl.cc

@@ -10,6 +10,7 @@
 #include "base/rand_util.h"
 #include "base/stl_util.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/thread_task_runner_handle.h"
 #include "base/threading/platform_thread.h"
 #include "base/time/time.h"
 #include "components/html_viewer/blink_resource_constants.h"

components/html_viewer/blink_platform_impl.h

@@ -6,7 +6,6 @@
 #define COMPONENTS_HTML_VIEWER_BLINK_PLATFORM_IMPL_H_
 
 #include "base/memory/scoped_ptr.h"
-#include "base/message_loop/message_loop.h"
 #include "base/threading/thread_local_storage.h"
 #include "base/timer/timer.h"
 #include "cc/blink/web_compositor_support_impl.h"