Reland of 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 691cad2f6417e1310317a2edcedbd44063dd263a..e98c527e03135cb50ba7ba059d5969d59cc43855 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 {
@@ -23,18 +24,20 @@ class RenderWidgetHostImpl;
 namespace devtools {
 namespace input {
 
-class InputHandler {
+class InputHandler : public RenderWidgetHost::InputEventObserver {
  public:
   typedef DevToolsProtocolClient::Response Response;
 
   InputHandler();
-  virtual ~InputHandler();
+  ~InputHandler() override;
 
   void SetRenderWidgetHost(RenderWidgetHostImpl* host);
   void SetClient(std::unique_ptr<Client> client);
   void OnSwapCompositorFrame(const cc::CompositorFrameMetadata& frame_metadata);
+  void Detached();
 
-  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,
@@ -48,7 +51,8 @@ class InputHandler {
                             const bool* is_keypad,
                             const bool* is_system_key);
 
-  Response DispatchMouseEvent(const std::string& type,
+  Response DispatchMouseEvent(DevToolsCommandId command_id,
+                              const std::string& type,
                               int x,
                               int y,
                               const int* modifiers,
@@ -101,6 +105,13 @@ class InputHandler {
       const double* timestamp);
 
  private:
+  // InputEventObserver
+  void OnInputEvent(const blink::WebInputEvent& event) override;
+  void OnInputEventAck(const blink::WebInputEvent& event) override;
+
+  void SendDispatchKeyEventResponse(DevToolsCommandId command_id);
+  void SendDispatchMouseEventResponse(DevToolsCommandId command_id);
+
   void SendSynthesizePinchGestureResponse(DevToolsCommandId command_id,
                                           SyntheticGesture::Result result);
 
@@ -125,8 +136,16 @@ class InputHandler {
                         DevToolsCommandId command_id,
                         SyntheticGesture::Result result);
 
+  void ClearPendingKeyCommands();
+  void ClearPendingMouseCommands();
+
   RenderWidgetHostImpl* host_;
   std::unique_ptr<Client> client_;
+  // DevToolsCommandIds for calls to Input.dispatchKey/MouseEvent that have been
+  // sent to the renderer, but that we haven't yet received an ack for.
+  bool input_queued_;
+  std::deque<DevToolsCommandId> pending_key_command_ids_;
+  std::deque<DevToolsCommandId> pending_mouse_command_ids_;
   float page_scale_factor_;
   gfx::SizeF scrollable_viewport_size_;
   base::WeakPtrFactory<InputHandler> weak_factory_;