Adds BeginFrameControl via DevTools.

cc/ipc/begin_frame_args_struct_traits.h

 // Copyright 2016 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.
 
 #ifndef CC_IPC_BEGIN_FRAME_ARGS_STRUCT_TRAITS_H_
 #define CC_IPC_BEGIN_FRAME_ARGS_STRUCT_TRAITS_H_
 
 #include "cc/ipc/begin_frame_args.mojom-shared.h"
 #include "cc/output/begin_frame_args.h"
 
@@ skipping 14 matching lines @@
   }
 
   static cc::mojom::BeginFrameArgsType type(const cc::BeginFrameArgs& args) {
     return static_cast<cc::mojom::BeginFrameArgsType>(args.type);
   }
 
   static bool on_critical_path(const cc::BeginFrameArgs& args) {
     return args.on_critical_path;
   }
 
+  static bool allow_latency_optimizations(const cc::BeginFrameArgs& args) {
+    return args.allow_latency_optimizations;
+  }
+
   static bool Read(cc::mojom::BeginFrameArgsDataView data,
                    cc::BeginFrameArgs* out) {
     if (!data.ReadFrameTime(&out->frame_time) ||
         !data.ReadDeadline(&out->deadline) ||
         !data.ReadInterval(&out->interval)) {
       return false;
     }
     out->type =
         static_cast<cc::BeginFrameArgs::BeginFrameArgsType>(data.type());
     out->on_critical_path = data.on_critical_path();
+    out->allow_latency_optimizations = data.allow_latency_optimizations();
     return true;
   }
 };
 
 }  // namespace mojo
 
 #endif  // CC_IPC_BEGIN_FRAME_ARGS_STRUCT_TRAITS_H_