[DevTools] Send ack early when paused in mouse move to keep events coming.

content/renderer/render_widget.h

Index: content/renderer/render_widget.h
diff --git a/content/renderer/render_widget.h b/content/renderer/render_widget.h
index a4f988db475f838a0c5e5fb4706be394af886bdb..b5e896adc1a2d27b6e02049c392daf12a78be30f 100644
--- a/content/renderer/render_widget.h
+++ b/content/renderer/render_widget.h
@@ -24,6 +24,7 @@
 #include "ipc/ipc_sender.h"
 #include "third_party/WebKit/public/platform/WebRect.h"
 #include "third_party/WebKit/public/web/WebCompositionUnderline.h"
+#include "third_party/WebKit/public/web/WebInputEvent.h"
 #include "third_party/WebKit/public/web/WebPopupType.h"
 #include "third_party/WebKit/public/web/WebTextDirection.h"
 #include "third_party/WebKit/public/web/WebTextInputInfo.h"
@@ -52,7 +53,6 @@ class SyncMessage;
 namespace blink {
 struct WebDeviceEmulationParams;
 class WebGestureEvent;
-class WebInputEvent;
 class WebKeyboardEvent;
 class WebMouseEvent;
 class WebTouchEvent;
@@ -188,6 +188,15 @@ class CONTENT_EXPORT RenderWidget
   virtual void InstrumentDidCancelFrame() {}
   virtual void InstrumentWillComposite() {}
 
+  // When paused in debugger, we send ack for mouse event early. This ensures
+  // that we continue receiving mouse moves and pass them to debugger. Returns
+  // whether we are paused in mouse move event and sent the ack.
+  bool SendAckForMouseMoveFromDebugger();
+
+  // When resumed from pause in debugger while handling mouse move,
+  // we should not send an extra ack (see SendAckForCurrentMouseMove).
+  void IgnoreAckForMouseMoveFromDebugger();
+
   bool UsingSynchronousRendererCompositor() const;
 
   // ScreenMetricsEmulator class manages screen emulation inside a render
@@ -573,8 +582,11 @@ class CONTENT_EXPORT RenderWidget
   // Are we currently handling an ime event?
   bool handling_ime_event_;
 
-  // Are we currently handling a touchstart event?
-  bool handling_touchstart_event_;
+  // Type of event we are currently handling.
+  blink::WebInputEvent::Type handling_event_type_;
+
+  // Whether we should not sent ack for current mouse move.
+  bool ignore_ack_for_mouse_move_from_debugger_;
 
   // True if we have requested this widget be closed.  No more messages will
   // be sent, except for a Close.