Add Keyboard Latency UMA Metrics.

content/browser/renderer_host/render_widget_host_impl.h

Index: content/browser/renderer_host/render_widget_host_impl.h
diff --git a/content/browser/renderer_host/render_widget_host_impl.h b/content/browser/renderer_host/render_widget_host_impl.h
index 7eee0fb8435478bc8421d0656512c4de7722df77..0d93c6cd163e507867e362501942326d6177b9f8 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -155,7 +155,9 @@ class CONTENT_EXPORT RenderWidgetHostImpl
   void SetActive(bool active) override;
   void ForwardMouseEvent(const blink::WebMouseEvent& mouse_event) override;
   void ForwardWheelEvent(const blink::WebMouseWheelEvent& wheel_event) override;
-  void ForwardKeyboardEvent(const NativeWebKeyboardEvent& key_event) override;
+  void ForwardKeyboardEventWithLatencyInfo(
+      const NativeWebKeyboardEvent& key_event,
+      const ui::LatencyInfo& latency) override;
   void ForwardGestureEvent(
       const blink::WebGestureEvent& gesture_event) override;
   RenderProcessHost* GetProcess() const override;
@@ -345,6 +347,7 @@ class CONTENT_EXPORT RenderWidgetHostImpl
   // aura.
   void ForwardKeyboardEventWithCommands(
       const NativeWebKeyboardEvent& key_event,
+      const ui::LatencyInfo& latency,
       const std::vector<EditCommand>* commands,
       bool* update_event = nullptr);
 
@@ -352,16 +355,15 @@ class CONTENT_EXPORT RenderWidgetHostImpl
   // when it has received a message.
   void ForwardGestureEventWithLatencyInfo(
       const blink::WebGestureEvent& gesture_event,
-      const ui::LatencyInfo& ui_latency) override;
+      const ui::LatencyInfo& latency) override;
   virtual void ForwardTouchEventWithLatencyInfo(
       const blink::WebTouchEvent& touch_event,
-      const ui::LatencyInfo& ui_latency);  // Virtual for testing.
-  void ForwardMouseEventWithLatencyInfo(
-      const blink::WebMouseEvent& mouse_event,
-      const ui::LatencyInfo& ui_latency);
+      const ui::LatencyInfo& latency);  // Virtual for testing.
+  void ForwardMouseEventWithLatencyInfo(const blink::WebMouseEvent& mouse_event,
+                                        const ui::LatencyInfo& latency);
   virtual void ForwardWheelEventWithLatencyInfo(
       const blink::WebMouseWheelEvent& wheel_event,
-      const ui::LatencyInfo& ui_latency);  // Virtual for testing.
+      const ui::LatencyInfo& latency);  // Virtual for testing.
 
   // Enables/disables touch emulation using mouse event. See TouchEmulator.
   void SetTouchEventEmulationEnabled(