Delay Input.dispatchKeyEvent response until after key event ack.

content/browser/devtools/protocol/input_handler.h

Index: content/browser/devtools/protocol/input_handler.h
diff --git a/content/browser/devtools/protocol/input_handler.h b/content/browser/devtools/protocol/input_handler.h
index 6e548a5cbcbd24e17c4b199fe3f843967fdc49d0..bc29edbd1ffd189fecc0d67c05714c03db5d68ce 100644
--- a/content/browser/devtools/protocol/input_handler.h
+++ b/content/browser/devtools/protocol/input_handler.h
@@ -10,6 +10,7 @@
 #include "content/browser/devtools/protocol/devtools_protocol_dispatcher.h"
 #include "content/browser/renderer_host/input/synthetic_gesture.h"
 #include "content/common/input/synthetic_smooth_scroll_gesture_params.h"
+#include "content/public/browser/render_widget_host.h"
 #include "ui/gfx/geometry/size_f.h"
 
 namespace cc {
@@ -27,18 +28,24 @@ class RenderWidgetHostImpl;
 namespace devtools {
 namespace input {
 
-class InputHandler {
+class InputHandler : public RenderWidgetHost::InputEventObserver {
  public:
   typedef DevToolsProtocolClient::Response Response;
 
   InputHandler();
-  virtual ~InputHandler();
+  ~InputHandler() override;
+
+  // InputEventObserver
+  void OnInputEvent(const blink::WebInputEvent& event) override {};
+  void OnInputEventAck(const blink::WebInputEvent& event, bool is_synthetic)
+      override;
 
   void SetRenderWidgetHost(RenderWidgetHostImpl* host);
   void SetClient(std::unique_ptr<Client> client);
   void OnSwapCompositorFrame(const cc::CompositorFrameMetadata& frame_metadata);
 
-  Response DispatchKeyEvent(const std::string& type,
+  Response DispatchKeyEvent(DevToolsCommandId command_id,
+                            const std::string& type,
                             const int* modifiers,
                             const double* timestamp,
                             const std::string* text,
@@ -99,6 +106,8 @@ class InputHandler {
                                 const std::string* gesture_source_type);
 
  private:
+  void SendDispatchKeyEventResponse(DevToolsCommandId command_id);
+
   void SendSynthesizePinchGestureResponse(DevToolsCommandId command_id,
                                           SyntheticGesture::Result result);
 
@@ -125,6 +134,9 @@ class InputHandler {
 
   RenderWidgetHostImpl* host_;
   std::unique_ptr<Client> client_;
+  // DevToolsCommandIds for calls to Input.dispatchKeyEvent that have been sent
+  // to the renderer, but that we haven't yet received an ack for.
+  std::queue<DevToolsCommandId> pending_key_event_ids_;
   float page_scale_factor_;
   gfx::SizeF scrollable_viewport_size_;
   base::WeakPtrFactory<InputHandler> weak_factory_;