Move cc/debug/latency_info to ui/base.

This structure would be useful in ui/surface, which can't depend on cc/.

BUG=

Review URL: https://chromiumcodereview.appspot.com/14999012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@202772 0039d316-1c4b-4281-b951-d872f2087c98

20 files changed, 39 insertions, 166 deletions

diff --git a/cc/DEPS b/cc/DEPS
index 5f4860f..00303d3 100644
--- a/cc/DEPS
+++ b/cc/DEPS
@@ -6,6 +6,7 @@ include_rules = [
   "+third_party/skia/include",
   "+third_party/khronos/GLES2/gl2.h",
   "+third_party/khronos/GLES2/gl2ext.h",
+  "+ui/base",
   "+ui/gfx",
   "+ui/gl",
   "+ui/surface",
diff --git a/cc/cc.gyp b/cc/cc.gyp
index 026134c..1447c26 100644
--- a/cc/cc.gyp
+++ b/cc/cc.gyp
@@ -60,8 +60,6 @@
       'debug/fake_web_graphics_context_3d.h',
       'debug/frame_rate_counter.cc',
       'debug/frame_rate_counter.h',
-      'debug/latency_info.cc',
-      'debug/latency_info.h',
       'debug/layer_tree_debug_state.cc',
       'debug/layer_tree_debug_state.h',
       'debug/overdraw_metrics.cc',
diff --git a/cc/debug/latency_info.cc b/cc/debug/latency_info.cc
deleted file mode 100644
index f59b07b..0000000
--- a/cc/debug/latency_info.cc
+++ /dev/null
@@ -1,61 +0,0 @@
-// Copyright (c) 2013 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.
-
-#include "cc/debug/latency_info.h"
-
-#include <algorithm>
-
-namespace cc {
-
-LatencyInfo::LatencyInfo() {
-}
-
-LatencyInfo::~LatencyInfo() {
-}
-
-void LatencyInfo::MergeWith(const LatencyInfo& other) {
-  for (LatencyMap::const_iterator b = other.latency_components.begin();
-      b != other.latency_components.end(); ++b) {
-    AddLatencyNumberWithTimestamp(b->first.first, b->first.second,
-                                  b->second.sequence_number,
-                                  b->second.event_time,
-                                  b->second.event_count);
-  }
-}
-
-void LatencyInfo::AddLatencyNumber(LatencyComponentType component,
-                                   int64 id, int64 component_sequence_number) {
-  AddLatencyNumberWithTimestamp(component, id, component_sequence_number,
-                                base::TimeTicks::Now(), 1);
-}
-
-void LatencyInfo::AddLatencyNumberWithTimestamp(
-    LatencyComponentType component, int64 id, int64 component_sequence_number,
-    base::TimeTicks time, uint32 event_count) {
-  LatencyMap::key_type key = std::make_pair(component, id);
-  LatencyMap::iterator f = latency_components.find(key);
-  if (f == latency_components.end()) {
-    LatencyComponent info = {component_sequence_number, time, event_count};
-    latency_components[key] = info;
-  } else {
-    f->second.sequence_number = std::max(component_sequence_number,
-                                         f->second.sequence_number);
-    uint32 new_count = event_count + f->second.event_count;
-    if (event_count > 0 && new_count != 0) {
-      // Do a weighted average, so that the new event_time is the average of
-      // the times of events currently in this structure with the time passed
-      // into this method.
-      f->second.event_time += (time - f->second.event_time) * event_count /
-          new_count;
-      f->second.event_count = new_count;
-    }
-  }
-}
-
-void LatencyInfo::Clear() {
-  latency_components.clear();
-}
-
-}  // namespace cc
-
diff --git a/cc/debug/latency_info.h b/cc/debug/latency_info.h
deleted file mode 100644
index e967caf..0000000
--- a/cc/debug/latency_info.h
+++ /dev/null
@@ -1,66 +0,0 @@
-// Copyright 2013 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_DEBUG_LATENCY_INFO_H_
-#define CC_DEBUG_LATENCY_INFO_H_
-
-#include <map>
-#include <utility>
-
-#include "base/basictypes.h"
-#include "base/time.h"
-#include "cc/base/cc_export.h"
-
-namespace cc {
-
-enum LatencyComponentType {
-  kRendererMainThread,
-  kRendererImplThread,
-  kBrowserMainThread,
-  kBrowserImplThread,
-  kInputEvent,
-};
-
-struct CC_EXPORT LatencyInfo {
-  struct LatencyComponent {
-    // Nondecreasing number that can be used to determine what events happened
-    // in the component at the time this struct was sent on to the next
-    // component.
-    int64 sequence_number;
-    // Average time of events that happened in this component.
-    base::TimeTicks event_time;
-    // Count of events that happened in this component
-    uint32 event_count;
-  };
-
-  // Map a Latency Component (with a component-specific int64 id) to a
-  // component info.
-  typedef std::map<std::pair<LatencyComponentType, int64>, LatencyComponent>
-      LatencyMap;
-
-  LatencyMap latency_components;
-
-  // This represents the final time that a frame is displayed it.
-  base::TimeTicks swap_timestamp;
-
-  LatencyInfo();
-
-  ~LatencyInfo();
-
-  void MergeWith(const LatencyInfo& other);
-
-  void AddLatencyNumber(LatencyComponentType component, int64 id,
-                        int64 component_sequence_number);
-  void AddLatencyNumberWithTimestamp(LatencyComponentType component,
-                                     int64 id, int64 component_sequence_number,
-                                     base::TimeTicks time,
-                                     uint32 event_count);
-
-  void Clear();
-};
-
-}  // namespace cc
-
-#endif  // CC_DEBUG_LATENCY_INFO_H_
-
diff --git a/cc/output/compositor_frame_metadata.h b/cc/output/compositor_frame_metadata.h
index 55ee9da..4e569bb 100644
--- a/cc/output/compositor_frame_metadata.h
+++ b/cc/output/compositor_frame_metadata.h
@@ -6,7 +6,7 @@
 #define CC_OUTPUT_COMPOSITOR_FRAME_METADATA_H_
 
 #include "cc/base/cc_export.h"
-#include "cc/debug/latency_info.h"
+#include "ui/base/latency_info.h"
 #include "ui/gfx/size_f.h"
 #include "ui/gfx/vector2d_f.h"
 
@@ -38,7 +38,7 @@ class CC_EXPORT CompositorFrameMetadata {
   gfx::Vector2dF location_bar_content_translation;
   float overdraw_bottom_height;
 
-  LatencyInfo latency_info;
+  ui::LatencyInfo latency_info;
 };
 
 }  // namespace cc
diff --git a/cc/output/delegating_renderer.cc b/cc/output/delegating_renderer.cc
index 3b5839e..ea034b0 100644
--- a/cc/output/delegating_renderer.cc
+++ b/cc/output/delegating_renderer.cc
@@ -156,7 +156,7 @@ void DelegatingRenderer::DrawFrame(
   resource_provider_->PrepareSendToParent(resources, &out_data.resource_list);
 }
 
-void DelegatingRenderer::SwapBuffers(const LatencyInfo& latency_info) {
+void DelegatingRenderer::SwapBuffers(const ui::LatencyInfo& latency_info) {
   TRACE_EVENT0("cc", "DelegatingRenderer::SwapBuffers");
 
   output_surface_->SendFrameToParentCompositor(&frame_for_swap_buffers_);
diff --git a/cc/output/delegating_renderer.h b/cc/output/delegating_renderer.h
index 6e659c0..ef44f79 100644
--- a/cc/output/delegating_renderer.h
+++ b/cc/output/delegating_renderer.h
@@ -32,7 +32,7 @@ class CC_EXPORT DelegatingRenderer : public Renderer {
 
   virtual void Finish() OVERRIDE {}
 
-  virtual void SwapBuffers(const LatencyInfo& latency_info) OVERRIDE;
+  virtual void SwapBuffers(const ui::LatencyInfo& latency_info) OVERRIDE;
 
   virtual void GetFramebufferPixels(void* pixels, gfx::Rect rect) OVERRIDE;
 
diff --git a/cc/output/gl_renderer.cc b/cc/output/gl_renderer.cc
index 7d37920..1afb384 100644
--- a/cc/output/gl_renderer.cc
+++ b/cc/output/gl_renderer.cc
@@ -1960,7 +1960,7 @@ void GLRenderer::Finish() {
   context_->finish();
 }
 
-void GLRenderer::SwapBuffers(const LatencyInfo& latency_info) {
+void GLRenderer::SwapBuffers(const ui::LatencyInfo& latency_info) {
   DCHECK(visible_);
   DCHECK(!is_backbuffer_discarded_);
 
diff --git a/cc/output/gl_renderer.h b/cc/output/gl_renderer.h
index d90b32f..d4b7e1a 100644
--- a/cc/output/gl_renderer.h
+++ b/cc/output/gl_renderer.h
@@ -61,7 +61,7 @@ class CC_EXPORT GLRenderer
 
   virtual void DoNoOp() OVERRIDE;
   // Puts backbuffer onscreen.
-  virtual void SwapBuffers(const LatencyInfo& latency_info) OVERRIDE;
+  virtual void SwapBuffers(const ui::LatencyInfo& latency_info) OVERRIDE;
 
   virtual void GetFramebufferPixels(void* pixels, gfx::Rect rect) OVERRIDE;
 
diff --git a/cc/output/gl_renderer_unittest.cc b/cc/output/gl_renderer_unittest.cc
index 7e1a438..48a5951 100644
--- a/cc/output/gl_renderer_unittest.cc
+++ b/cc/output/gl_renderer_unittest.cc
@@ -268,7 +268,7 @@ class GLRendererTest : public testing::Test {
 
   virtual void SetUp() { renderer_.Initialize(); }
 
-  void SwapBuffers() { renderer_.SwapBuffers(LatencyInfo()); }
+  void SwapBuffers() { renderer_.SwapBuffers(ui::LatencyInfo()); }
 
   FrameCountingMemoryAllocationSettingContext* Context() {
     return static_cast<FrameCountingMemoryAllocationSettingContext*>(
@@ -1482,8 +1482,8 @@ class MockOutputSurface : public OutputSurface {
   MOCK_METHOD0(DiscardBackbuffer, void());
   MOCK_METHOD2(Reshape, void(gfx::Size size, float scale_factor));
   MOCK_METHOD0(BindFramebuffer, void());
-  MOCK_METHOD2(PostSubBuffer, void(gfx::Rect rect, const LatencyInfo&));
-  MOCK_METHOD1(SwapBuffers, void(const LatencyInfo&));
+  MOCK_METHOD2(PostSubBuffer, void(gfx::Rect rect, const ui::LatencyInfo&));
+  MOCK_METHOD1(SwapBuffers, void(const ui::LatencyInfo&));
 };
 
 class MockOutputSurfaceTest : public testing::Test, public FakeRendererClient {
@@ -1494,7 +1494,7 @@ class MockOutputSurfaceTest : public testing::Test, public FakeRendererClient {
 
   virtual void SetUp() { EXPECT_TRUE(renderer_.Initialize()); }
 
-  void SwapBuffers() { renderer_.SwapBuffers(LatencyInfo()); }
+  void SwapBuffers() { renderer_.SwapBuffers(ui::LatencyInfo()); }
 
   void DrawFrame() {
     gfx::Rect viewport_rect(DeviceViewportSize());
@@ -1536,31 +1536,31 @@ TEST_F(MockOutputSurfaceTest, DrawFrameAndSwap) {
   DrawFrame();
 
   EXPECT_CALL(output_surface_, SwapBuffers(_)).Times(1);
-  renderer_.SwapBuffers(LatencyInfo());
+  renderer_.SwapBuffers(ui::LatencyInfo());
 }
 
 TEST_F(MockOutputSurfaceTest, DrawFrameAndResizeAndSwap) {
   DrawFrame();
   EXPECT_CALL(output_surface_, SwapBuffers(_)).Times(1);
-  renderer_.SwapBuffers(LatencyInfo());
+  renderer_.SwapBuffers(ui::LatencyInfo());
 
   set_viewport_and_scale(gfx::Size(2, 2), 2.f);
   renderer_.ViewportChanged();
 
   DrawFrame();
   EXPECT_CALL(output_surface_, SwapBuffers(_)).Times(1);
-  renderer_.SwapBuffers(LatencyInfo());
+  renderer_.SwapBuffers(ui::LatencyInfo());
 
   DrawFrame();
   EXPECT_CALL(output_surface_, SwapBuffers(_)).Times(1);
-  renderer_.SwapBuffers(LatencyInfo());
+  renderer_.SwapBuffers(ui::LatencyInfo());
 
   set_viewport_and_scale(gfx::Size(1, 1), 1.f);
   renderer_.ViewportChanged();
 
   DrawFrame();
   EXPECT_CALL(output_surface_, SwapBuffers(_)).Times(1);
-  renderer_.SwapBuffers(LatencyInfo());
+  renderer_.SwapBuffers(ui::LatencyInfo());
 }
 
 class MockOutputSurfaceTestWithPartialSwap : public MockOutputSurfaceTest {
@@ -1576,7 +1576,7 @@ TEST_F(MockOutputSurfaceTestWithPartialSwap, DrawFrameAndSwap) {
   DrawFrame();
 
   EXPECT_CALL(output_surface_, PostSubBuffer(_, _)).Times(1);
-  renderer_.SwapBuffers(LatencyInfo());
+  renderer_.SwapBuffers(ui::LatencyInfo());
 }
 
 class MockOutputSurfaceTestWithSendCompositorFrame
diff --git a/cc/output/output_surface.cc b/cc/output/output_surface.cc
index ffc0b2a..6c46769 100644
--- a/cc/output/output_surface.cc
+++ b/cc/output/output_surface.cc
@@ -121,7 +121,7 @@ void OutputSurface::BindFramebuffer() {
   context3d_->bindFramebuffer(GL_FRAMEBUFFER, 0);
 }
 
-void OutputSurface::SwapBuffers(const LatencyInfo& latency_info) {
+void OutputSurface::SwapBuffers(const ui::LatencyInfo& latency_info) {
   DCHECK(context3d_);
   // Note that currently this has the same effect as SwapBuffers; we should
   // consider exposing a different entry point on WebGraphicsContext3D.
@@ -129,7 +129,7 @@ void OutputSurface::SwapBuffers(const LatencyInfo& latency_info) {
 }
 
 void OutputSurface::PostSubBuffer(gfx::Rect rect,
-                                  const LatencyInfo& latency_info) {
+                                  const ui::LatencyInfo& latency_info) {
   DCHECK(context3d_);
   context3d_->postSubBufferCHROMIUM(
       rect.x(), rect.y(), rect.width(), rect.height());
diff --git a/cc/output/output_surface.h b/cc/output/output_surface.h
index fb6f0b9..a021ebf 100644
--- a/cc/output/output_surface.h
+++ b/cc/output/output_surface.h
@@ -11,6 +11,8 @@
 #include "cc/output/software_output_device.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
 
+namespace ui { struct LatencyInfo; }
+
 namespace gfx {
 class Rect;
 class Size;
@@ -21,7 +23,6 @@ namespace cc {
 class CompositorFrame;
 class OutputSurfaceClient;
 class OutputSurfaceCallbacks;
-struct LatencyInfo;
 
 // Represents the output surface for a compositor. The compositor owns
 // and manages its destruction. Its lifetime is:
@@ -91,8 +92,8 @@ class CC_EXPORT OutputSurface {
 
   virtual void BindFramebuffer();
 
-  virtual void PostSubBuffer(gfx::Rect rect, const LatencyInfo&);
-  virtual void SwapBuffers(const LatencyInfo&);
+  virtual void PostSubBuffer(gfx::Rect rect, const ui::LatencyInfo&);
+  virtual void SwapBuffers(const ui::LatencyInfo&);
 
   // Notifies frame-rate smoothness preference. If true, all non-critical
   // processing should be stopped, or lowered in priority.
diff --git a/cc/output/renderer.h b/cc/output/renderer.h
index 5592090..aaf9fd7 100644
--- a/cc/output/renderer.h
+++ b/cc/output/renderer.h
@@ -7,10 +7,10 @@
 
 #include "base/basictypes.h"
 #include "cc/base/cc_export.h"
-#include "cc/debug/latency_info.h"
 #include "cc/quads/render_pass.h"
 #include "cc/resources/managed_memory_policy.h"
 #include "cc/trees/layer_tree_host.h"
+#include "ui/base/latency_info.h"
 
 namespace cc {
 
@@ -69,7 +69,7 @@ class CC_EXPORT Renderer {
   virtual void DoNoOp() {}
 
   // Puts backbuffer onscreen.
-  virtual void SwapBuffers(const LatencyInfo& latency_info) = 0;
+  virtual void SwapBuffers(const ui::LatencyInfo& latency_info) = 0;
 
   virtual void GetFramebufferPixels(void* pixels, gfx::Rect rect) = 0;
 
diff --git a/cc/output/software_renderer.cc b/cc/output/software_renderer.cc
index 4a337ff..b555b57 100644
--- a/cc/output/software_renderer.cc
+++ b/cc/output/software_renderer.cc
@@ -107,7 +107,7 @@ void SoftwareRenderer::FinishDrawingFrame(DrawingFrame* frame) {
   }
 }
 
-void SoftwareRenderer::SwapBuffers(const LatencyInfo& latency_info) {
+void SoftwareRenderer::SwapBuffers(const ui::LatencyInfo& latency_info) {
   if (Settings().compositor_frame_message)
     output_surface_->SendFrameToParentCompositor(&compositor_frame_);
 }
diff --git a/cc/output/software_renderer.h b/cc/output/software_renderer.h
index 72a5052..cbaf1d3 100644
--- a/cc/output/software_renderer.h
+++ b/cc/output/software_renderer.h
@@ -35,7 +35,7 @@ class CC_EXPORT SoftwareRenderer : public DirectRenderer {
   virtual const RendererCapabilities& Capabilities() const OVERRIDE;
   virtual void ViewportChanged() OVERRIDE;
   virtual void Finish() OVERRIDE;
-  virtual void SwapBuffers(const LatencyInfo& latency_info) OVERRIDE;
+  virtual void SwapBuffers(const ui::LatencyInfo& latency_info) OVERRIDE;
   virtual void GetFramebufferPixels(void* pixels, gfx::Rect rect) OVERRIDE;
   virtual void SetVisible(bool visible) OVERRIDE;
   virtual void SendManagedMemoryStats(
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index 6b7d772..966ff9d 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -596,7 +596,7 @@ void LayerTreeHost::SetVisible(bool visible) {
   proxy_->SetVisible(visible);
 }
 
-void LayerTreeHost::SetLatencyInfo(const LatencyInfo& latency_info) {
+void LayerTreeHost::SetLatencyInfo(const ui::LatencyInfo& latency_info) {
   latency_info_.MergeWith(latency_info);
 }
 
diff --git a/cc/trees/layer_tree_host.h b/cc/trees/layer_tree_host.h
index e5dd380..4226c23 100644
--- a/cc/trees/layer_tree_host.h
+++ b/cc/trees/layer_tree_host.h
@@ -18,7 +18,6 @@
 #include "cc/animation/animation_events.h"
 #include "cc/base/cc_export.h"
 #include "cc/base/scoped_ptr_vector.h"
-#include "cc/debug/latency_info.h"
 #include "cc/input/input_handler.h"
 #include "cc/input/scrollbar.h"
 #include "cc/input/top_controls_state.h"
@@ -33,6 +32,7 @@
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkPicture.h"
+#include "ui/base/latency_info.h"
 #include "ui/gfx/rect.h"
 
 namespace WebKit { class WebGraphicsContext3D; }
@@ -216,7 +216,7 @@ class CC_EXPORT LayerTreeHost : NON_EXPORTED_BASE(public RateLimiterClient) {
   void ApplyScrollAndScale(const ScrollAndScaleSet& info);
 
   void SetImplTransform(const gfx::Transform& transform);
-  void SetLatencyInfo(const LatencyInfo& latency_info);
+  void SetLatencyInfo(const ui::LatencyInfo& latency_info);
 
   void StartRateLimiter(WebKit::WebGraphicsContext3D* context3d);
   void StopRateLimiter(WebKit::WebGraphicsContext3D* context3d);
@@ -347,7 +347,7 @@ class CC_EXPORT LayerTreeHost : NON_EXPORTED_BASE(public RateLimiterClient) {
 
   bool in_paint_layer_contents_;
 
-  LatencyInfo latency_info_;
+  ui::LatencyInfo latency_info_;
 
   static const int kTotalFramesToUseForLCDTextMetrics = 50;
   int total_frames_used_for_lcd_text_metrics_;
diff --git a/cc/trees/layer_tree_host_impl.h b/cc/trees/layer_tree_host_impl.h
index 15cc599..02c0a90 100644
--- a/cc/trees/layer_tree_host_impl.h
+++ b/cc/trees/layer_tree_host_impl.h
@@ -14,7 +14,6 @@
 #include "cc/animation/animation_events.h"
 #include "cc/animation/animation_registrar.h"
 #include "cc/base/cc_export.h"
-#include "cc/debug/latency_info.h"
 #include "cc/input/input_handler.h"
 #include "cc/input/layer_scroll_offset_delegate.h"
 #include "cc/input/top_controls_manager_client.h"
@@ -27,6 +26,7 @@
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkPicture.h"
+#include "ui/base/latency_info.h"
 #include "ui/gfx/rect.h"
 
 namespace cc {
@@ -146,7 +146,7 @@ class CC_EXPORT LayerTreeHostImpl
     LayerImplList will_draw_layers;
     bool contains_incomplete_tile;
     bool has_no_damage;
-    LatencyInfo latency_info;
+    ui::LatencyInfo latency_info;
 
     // RenderPassSink implementation.
     virtual void AppendRenderPass(scoped_ptr<RenderPass> render_pass) OVERRIDE;
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index e8d9dc2..e5705ca 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -554,11 +554,11 @@ void LayerTreeImpl::UpdateRootScrollLayerSizeDelta() {
       scrollable_viewport_size - original_viewport_size);
 }
 
-void LayerTreeImpl::SetLatencyInfo(const LatencyInfo& latency_info) {
+void LayerTreeImpl::SetLatencyInfo(const ui::LatencyInfo& latency_info) {
   latency_info_.MergeWith(latency_info);
 }
 
-const LatencyInfo& LayerTreeImpl::GetLatencyInfo() {
+const ui::LatencyInfo& LayerTreeImpl::GetLatencyInfo() {
   return latency_info_;
 }
 
diff --git a/cc/trees/layer_tree_impl.h b/cc/trees/layer_tree_impl.h
index 3af49ca..304dbb9 100644
--- a/cc/trees/layer_tree_impl.h
+++ b/cc/trees/layer_tree_impl.h
@@ -10,8 +10,8 @@
 
 #include "base/hash_tables.h"
 #include "base/values.h"
-#include "cc/debug/latency_info.h"
 #include "cc/layers/layer_impl.h"
+#include "ui/base/latency_info.h"
 
 #if defined(COMPILER_GCC)
 namespace BASE_HASH_NAMESPACE {
@@ -186,8 +186,8 @@ class CC_EXPORT LayerTreeImpl {
   void SetRootLayerScrollOffsetDelegate(
       LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate);
 
-  void SetLatencyInfo(const LatencyInfo& latency_info);
-  const LatencyInfo& GetLatencyInfo();
+  void SetLatencyInfo(const ui::LatencyInfo& latency_info);
+  const ui::LatencyInfo& GetLatencyInfo();
   void ClearLatencyInfo();
 
   void WillModifyTilePriorities();
@@ -233,7 +233,7 @@ class CC_EXPORT LayerTreeImpl {
   // structural differences relative to the active tree.
   bool needs_full_tree_sync_;
 
-  LatencyInfo latency_info_;
+  ui::LatencyInfo latency_info_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeImpl);
 };