WIP: Plumbing input event latency reporting through Mus GPU.

gpu/ipc/in_process_command_buffer.cc

Index: gpu/ipc/in_process_command_buffer.cc
diff --git a/gpu/ipc/in_process_command_buffer.cc b/gpu/ipc/in_process_command_buffer.cc
index 1934450bc4db1a16399aed3432636b3c2c0b475b..028833c5e2252cb6a202c96618b595703f4db6af 100644
--- a/gpu/ipc/in_process_command_buffer.cc
+++ b/gpu/ipc/in_process_command_buffer.cc
@@ -284,6 +284,10 @@ bool InProcessCommandBuffer::Initialize(
   return result;
 }
 
+void InProcessCommandBuffer::SetLatencyInfo(const std::vector<ui::LatencyInfo>& latency_info) {
+  latency_info_.insert(latency_info_.end(), latency_info.begin(), latency_info.end());
+}
+
 bool InProcessCommandBuffer::InitializeOnGpuThread(
     const InitializeOnGpuThreadParams& params) {
   CheckSequencedThread();
@@ -555,6 +559,13 @@ void InProcessCommandBuffer::FlushOnGpuThread(int32_t put_offset) {
   ScopedEvent handle_flush(&flush_event_);
   base::AutoLock lock(command_buffer_lock_);
 
+  if (ui::LatencyInfo::Verify(latency_info_,
+                              "InProcessCommandBuffer::FlushOnGpuThread") &&
+      !latency_info_callback_.is_null()) {
+    latency_info_callback_.Run(latency_info_);
+  }
+  latency_info_.clear();
+
   command_buffer_->Flush(put_offset);
   // Update state before signaling the flush event.
   UpdateLastStateOnGpuThread();
@@ -1014,7 +1025,7 @@ const gles2::FeatureInfo* InProcessCommandBuffer::GetFeatureInfo() const {
 
 void InProcessCommandBuffer::SetLatencyInfoCallback(
     const LatencyInfoCallback& callback) {
-  // TODO(fsamuel): Implement this.
+  latency_info_callback_ = callback;
 }
 
 void InProcessCommandBuffer::UpdateVSyncParameters(base::TimeTicks timebase,