Use compositor_frame typemap in Blink

ui/events/mojo/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//mojo/public/tools/bindings/mojom.gni")
 
 mojom("interfaces") {
   sources = [
     "event.mojom",
     "event_constants.mojom",
@@ skipping 14 matching lines @@
   sources = [
     "traits_test_service.mojom",
   ]
 
   public_deps = [
     ":interfaces",
   ]
 
   use_new_wrapper_types = false
 }
+
+group("struct_traits") {
+  public_deps = [
+    ":struct_traits_sources",

[yzshen1, 2016/09/01 00:02:54]

Can we delete this and rename struct_traits_sources to struct_traits? (Same
comment for some other files.)

+  ]
+}
+
+source_set("struct_traits_sources") {
+  sources = [
+    "latency_info_struct_traits.cc",
+    "latency_info_struct_traits.h",
+  ]
+  deps = [
+    ":interfaces_shared_cpp_sources",
+    "//mojo/common",
+    "//mojo/public/cpp/bindings",
+    "//ui/events:events_base",
+    "//ui/gfx/geometry/mojo:struct_traits",
+  ]
+}