Update legacy Tuple-using code.

content/browser/renderer_host/render_widget_host_impl.cc

Index: content/browser/renderer_host/render_widget_host_impl.cc
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc
index 986bda4ecce621a7506bd15622cf455f13b29864..4cf0f14cb7f2eb495244eb66ef5dbec438a80b60 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -1428,10 +1428,10 @@ bool RenderWidgetHostImpl::OnSwapCompositorFrame(
   if (!ViewHostMsg_SwapCompositorFrame::Read(&message, &param))
     return false;
   scoped_ptr<cc::CompositorFrame> frame(new cc::CompositorFrame);
-  uint32 output_surface_id = param.a;
-  param.b.AssignTo(frame.get());
+  uint32 output_surface_id = get<0>(param);
+  get<1>(param).AssignTo(frame.get());
   std::vector<IPC::Message> messages_to_deliver_with_frame;
-  messages_to_deliver_with_frame.swap(param.c);
+  messages_to_deliver_with_frame.swap(get<2>(param));
 
   latency_tracker_.OnSwapCompositorFrame(&frame->metadata.latency_info);