Remove gpu side LatencyInfo merging

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index fd3a7f22fe71ae0b451b6bf898700cf56445627f..5dcc7dd12ebbc41a5897e94502d16cffcc82401f 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -162,6 +162,10 @@ static const char* kSiteProcessMapKeyName = "content_site_process_map";
 namespace content {
 namespace {
 
+// Maximal number of LatencyInfo that can be contained in
+// ViewHostMsg_CompositorSurfaceBuffersSwapped_Params.
+const unsigned int kMaxLatencyInfoNumber = 100;
+
 void CacheShaderInfo(int32 id, base::FilePath path) {
   ShaderCacheFactory::GetInstance()->SetCacheInfo(id, path);
 }
@@ -1987,6 +1991,7 @@ void RenderProcessHostImpl::OnCompositorSurfaceBuffersSwappedNoHost(
       const ViewHostMsg_CompositorSurfaceBuffersSwapped_Params& params) {
   TRACE_EVENT0("renderer_host",
                "RenderWidgetHostImpl::OnCompositorSurfaceBuffersSwappedNoHost");
+  CHECK(params.latency_info.size() < kMaxLatencyInfoNumber);

[jln (very slow on Chromium), 2014/01/14 00:32:51]

The problem with this approach is that is gives a trivial denial of service from
a compromised renderer to the browser.

It's not a huge issue, but we would rather avoid that. Could we log an error and
ignore the message instead?

[Yufeng Shen (Slow to review), 2014/01/14 00:47:14]

Done.

   AcceleratedSurfaceMsg_BufferPresented_Params ack_params;
   ack_params.sync_point = 0;
   RenderWidgetHostImpl::AcknowledgeBufferPresent(params.route_id,