Delay Input.dispatchKeyEvent response until after key event ack.

content/browser/devtools/protocol/input_handler.h

 // Copyright 2014 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 CONTENT_BROWSER_DEVTOOLS_PROTOCOL_INPUT_HANDLER_H_
 #define CONTENT_BROWSER_DEVTOOLS_PROTOCOL_INPUT_HANDLER_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #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 {
 class CompositorFrameMetadata;
 }
 
 namespace gfx {
 class Point;
 }
 
 namespace content {
 
 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 was_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,
                             const std::string* unmodified_text,
                             const std::string* key_identifier,
                             const std::string* code,
                             const std::string* key,
                             const int* windows_virtual_key_code,
                             const int* native_virtual_key_code,
                             const bool* auto_repeat,
@@ skipping 40 matching lines @@
                                    const std::string* interaction_marker_name);
 
   Response SynthesizeTapGesture(DevToolsCommandId command_id,
                                 int x,
                                 int y,
                                 const int* duration,
                                 const int* tap_count,
                                 const std::string* gesture_source_type);
 
  private:
+  void SendDispatchKeyEventResponse(DevToolsCommandId command_id);
+
   void SendSynthesizePinchGestureResponse(DevToolsCommandId command_id,
                                           SyntheticGesture::Result result);
 
   void SendSynthesizeScrollGestureResponse(DevToolsCommandId command_id,
                                            SyntheticGesture::Result result);
 
   void SendSynthesizeTapGestureResponse(DevToolsCommandId command_id,
                                         bool send_success,
                                         SyntheticGesture::Result result);
 
   void SynthesizeRepeatingScroll(
       SyntheticSmoothScrollGestureParams gesture_params,
       int repeat_count,
       base::TimeDelta repeat_delay,
       std::string interaction_marker_name,
       DevToolsCommandId command_id);
 
   void OnScrollFinished(SyntheticSmoothScrollGestureParams gesture_params,
                         int repeat_count,
                         base::TimeDelta repeat_delay,
                         std::string interaction_marker_name,
                         DevToolsCommandId command_id,
                         SyntheticGesture::Result result);
 
   RenderWidgetHostImpl* host_;
   std::unique_ptr<Client> client_;
+  std::queue<DevToolsCommandId> pending_key_event_ids_;

[tdresser, 2016/10/12 19:49:36]

Can you add a comment here explaining what we're doing?

[samuong, 2016/10/13 22:59:10]

Done.

   float page_scale_factor_;
   gfx::SizeF scrollable_viewport_size_;
   base::WeakPtrFactory<InputHandler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(InputHandler);
 };
 
 }  // namespace input
 }  // namespace devtools
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DEVTOOLS_PROTOCOL_INPUT_HANDLER_H_