Send input event IPCs directly from the UI thread

content/public/test/mock_render_process_host.cc

Index: content/public/test/mock_render_process_host.cc
diff --git a/content/public/test/mock_render_process_host.cc b/content/public/test/mock_render_process_host.cc
index 43b47a342ffb39f632e07b907dad43de30a182f3..dd10d04b7a4aa6c85e0f5871465730bed760fca9 100644
--- a/content/public/test/mock_render_process_host.cc
+++ b/content/public/test/mock_render_process_host.cc
@@ -240,7 +240,15 @@ bool MockRenderProcessHost::InSameStoragePartition(
 }
 
 IPC::ChannelProxy* MockRenderProcessHost::GetChannel() {
-  return NULL;
+  return nullptr;
+}
+
+IPC::Sender* MockRenderProcessHost::GetImmediateSender() {
+  return this;
+}
+
+IPC::Sender* MockRenderProcessHost::GetIOThreadSender() {
+  return this;
 }
 
 void MockRenderProcessHost::AddFilter(BrowserMessageFilter* filter) {