Revert "Clean up DidStopFlinging IPC"

This reverts commit 7cb247dd.

Reason for revert: Check to see if the crash report in crbug.com/868849 goes away or not.

Original change's description:
> Clean up DidStopFlinging IPC
> 
> This cl also removes TouchscreenFlingInProgress function that is no
> longer needed.
> 
> Bug: 249063
> Change-Id: Icc939d654cdfe0cf38c843933f2fd469f843b74c
> Reviewed-on: https://chromium-review.googlesource.com/1145784
> Reviewed-by: Dave Tapuska <dtapuska@chromium.org>
> Reviewed-by: Ken Buchanan <kenrb@chromium.org>
> Reviewed-by: Philip Rogers <pdr@chromium.org>
> Commit-Queue: Sahel Sharify <sahel@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#578410}

TBR=kenrb@chromium.org,pdr@chromium.org,dtapuska@chromium.org,sahel@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 249063
Change-Id: Iee7200d3c4e388fccbc2dc6b86997a07a3a03f0a
Reviewed-on: https://chromium-review.googlesource.com/1155169Reviewed-by: Sahel Sharify <sahel@chromium.org>
Commit-Queue: Sahel Sharify <sahel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579166}

content/browser/renderer_host/input/fling_controller.cc

@@ -449,6 +449,11 @@ bool FlingController::FlingCancellationIsDeferred() const {
   return fling_booster_ && fling_booster_->fling_cancellation_is_deferred();
 }
 
+bool FlingController::TouchscreenFlingInProgress() const {
+  return fling_in_progress_ && current_fling_parameters_.source_device ==
+                                   blink::kWebGestureDeviceTouchscreen;
+}
+
 gfx::Vector2dF FlingController::CurrentFlingVelocity() const {
   return current_fling_parameters_.velocity;
 }

content/browser/renderer_host/input/fling_controller.h

@@ -99,6 +99,8 @@ class CONTENT_EXPORT FlingController {
 
   bool FlingCancellationIsDeferred() const;
 
+  bool TouchscreenFlingInProgress() const;
+
   gfx::Vector2dF CurrentFlingVelocity() const;
 
   // Returns the |TouchpadTapSuppressionController| instance.

content/browser/renderer_host/input/gesture_event_queue.cc

@@ -94,6 +94,9 @@ bool GestureEventQueue::FlingCancellationIsDeferred() const {
   return fling_controller_.FlingCancellationIsDeferred();
 }
 
+bool GestureEventQueue::TouchscreenFlingInProgress() const {
+  return fling_controller_.TouchscreenFlingInProgress();
+}
 gfx::Vector2dF GestureEventQueue::CurrentFlingVelocity() const {
   return fling_controller_.CurrentFlingVelocity();
 }

content/browser/renderer_host/input/gesture_event_queue.h

@@ -117,6 +117,8 @@ class CONTENT_EXPORT GestureEventQueue {
 
   bool FlingCancellationIsDeferred() const;
 
+  bool TouchscreenFlingInProgress() const;
+
   gfx::Vector2dF CurrentFlingVelocity() const;
 
   void set_debounce_interval_time_ms_for_testing(int interval_ms) {

content/browser/renderer_host/input/input_router_client.h

@@ -51,6 +51,9 @@ class CONTENT_EXPORT InputRouterClient {
   // from the renderer.
   virtual void OnSetWhiteListedTouchAction(cc::TouchAction touch_action) = 0;
 
+  // Called when a renderer fling has terminated.
+  virtual void DidStopFlinging() = 0;
+
   // Called when a GSB has started scrolling a viewport.
   virtual void DidStartScrollingViewport() = 0;
 

content/browser/renderer_host/input/input_router_impl.cc

@@ -257,6 +257,15 @@ void InputRouterImpl::DidOverscroll(const ui::DidOverscrollParams& params) {
   client_->DidOverscroll(fling_updated_params);
 }
 
+void InputRouterImpl::DidStopFlinging() {
+  DCHECK_GT(active_renderer_fling_count_, 0);
+  // Note that we're only guaranteed to get a fling end notification from the
+  // renderer, not from any other consumers. Consequently, the GestureEventQueue
+  // cannot use this bookkeeping for logic like tap suppression.
+  --active_renderer_fling_count_;
+  client_->DidStopFlinging();
+}
+
 void InputRouterImpl::DidStartScrollingViewport() {
   client_->DidStartScrollingViewport();
 }
@@ -363,6 +372,10 @@ void InputRouterImpl::OnFilteringTouchEvent(const WebTouchEvent& touch_event) {
   output_stream_validator_.Validate(touch_event);
 }
 
+bool InputRouterImpl::TouchscreenFlingInProgress() {
+  return gesture_event_queue_.TouchscreenFlingInProgress();
+}
+
 void InputRouterImpl::SendGestureEventImmediately(
     const GestureEventWithLatencyInfo& gesture_event) {
   mojom::WidgetInputHandler::DispatchEventCallback callback = base::BindOnce(
@@ -548,6 +561,11 @@ void InputRouterImpl::GestureEventHandled(
                InputEventAckStateToString(state));
   if (source != InputEventAckSource::BROWSER)
     client_->DecrementInFlightEventCount(source);
+  if (gesture_event.event.GetType() ==
+          blink::WebInputEvent::kGestureFlingStart &&
+      state == INPUT_EVENT_ACK_STATE_CONSUMED) {
+    ++active_renderer_fling_count_;
+  }
 
   if (overscroll) {
     DCHECK_EQ(WebInputEvent::kGestureScrollUpdate,

content/browser/renderer_host/input/input_router_impl.h

@@ -93,6 +93,7 @@ class CONTENT_EXPORT InputRouterImpl : public InputRouter,
                                  uint32_t unique_touch_event_id,
                                  InputEventAckState state) override;
   void DidOverscroll(const ui::DidOverscrollParams& params) override;
+  void DidStopFlinging() override;
   void ImeCancelComposition() override;
   void DidStartScrollingViewport() override;
   void ImeCompositionRangeChanged(
@@ -126,6 +127,7 @@ class CONTENT_EXPORT InputRouterImpl : public InputRouter,
                        InputEventAckSource ack_source,
                        InputEventAckState ack_result) override;
   void OnFilteringTouchEvent(const blink::WebTouchEvent& touch_event) override;
+  bool TouchscreenFlingInProgress() override;
 
   // GestureEventFilterClient
   void SendGestureEventImmediately(

content/browser/renderer_host/input/input_router_impl_unittest.cc

@@ -134,6 +134,8 @@ class MockInputRouterImplClient : public InputRouterImplClient {
     input_router_client_.DidOverscroll(params);
   }
 
+  void DidStopFlinging() override { input_router_client_.DidStopFlinging(); }
+
   void DidStartScrollingViewport() override {
     input_router_client_.DidStartScrollingViewport();
   }

content/browser/renderer_host/input/mock_input_router_client.cc

@@ -60,6 +60,9 @@ void MockInputRouterClient::OnSetWhiteListedTouchAction(
   white_listed_touch_action_ = white_listed_touch_action;
 }
 
+void MockInputRouterClient::DidStopFlinging() {
+}
+
 void MockInputRouterClient::DidStartScrollingViewport() {}
 
 void MockInputRouterClient::ForwardGestureEventWithLatencyInfo(

content/browser/renderer_host/input/mock_input_router_client.h

@@ -33,6 +33,7 @@ class MockInputRouterClient : public InputRouterClient,
   void OnHasTouchEventHandlers(bool has_handlers) override;
   void DidOverscroll(const ui::DidOverscrollParams& params) override;
   void OnSetWhiteListedTouchAction(cc::TouchAction touch_action) override;
+  void DidStopFlinging() override;
   void DidStartScrollingViewport() override;
   void ForwardWheelEventWithLatencyInfo(
       const blink::WebMouseWheelEvent& wheel_event,

content/browser/renderer_host/input/passthrough_touch_event_queue.h

@@ -33,6 +33,8 @@ class CONTENT_EXPORT PassthroughTouchEventQueueClient {
 
   virtual void OnFilteringTouchEvent(
       const blink::WebTouchEvent& touch_event) = 0;
+
+  virtual bool TouchscreenFlingInProgress() = 0;
 };
 
 // A queue that processes a touch-event and forwards it on to the

content/browser/renderer_host/input/passthrough_touch_event_queue_unittest.cc

@@ -94,6 +94,8 @@ class PassthroughTouchEventQueueTest : public testing::Test,
   void OnFilteringTouchEvent(const blink::WebTouchEvent& touch_event) override {
   }
 
+  bool TouchscreenFlingInProgress() override { return false; }
+
  protected:
   void SetUpForTouchMoveSlopTesting(double slop_length_dips) {
     slop_length_dips_ = slop_length_dips;

content/browser/renderer_host/render_widget_host_impl.h

@@ -713,7 +713,7 @@ class CONTENT_EXPORT RenderWidgetHostImpl
   // Returns the keyboard layout mapping.
   base::flat_map<std::string, std::string> GetKeyboardLayoutMap();
 
-  void DidStopFlinging();
+  void DidStopFlinging() override;
 
   void GetContentRenderingTimeoutFrom(RenderWidgetHostImpl* other);
 

content/common/input/input_handler.mojom

@@ -174,6 +174,9 @@ interface WidgetInputHandlerHost {
   // restrictions on the root scroll offset.
   DidOverscroll(DidOverscrollParams params);
 
+  // Sent by the compositor when a fling animation is stopped.
+  DidStopFlinging();
+
   // Sent by the compositor when a GSB has started scrolling the viewport.
   DidStartScrollingViewport();
 

content/renderer/input/input_handler_manager_client.h

@@ -49,6 +49,7 @@ class CONTENT_EXPORT InputHandlerManagerClient {
   // Otherwise |DidOverscroll| will be fired.
   virtual void DidOverscroll(int routing_id,
                              const ui::DidOverscrollParams& params) = 0;
+  virtual void DidStopFlinging(int routing_id) = 0;
   virtual void DidStartScrollingViewport(int routing_id) = 0;
   virtual void DispatchNonBlockingEventToMainThread(
       int routing_id,

third_party/blink/public/platform/web_layer_tree_view.h

@@ -145,6 +145,9 @@ class WebLayerTreeView {
   // dirty.
   virtual void SetNeedsBeginFrame() {}
 
+  // Relays the end of a fling animation.
+  virtual void DidStopFlinging() {}
+
   // Run layout and paint of all pending document changes asynchronously.
   virtual void LayoutAndPaintAsync(base::OnceClosure callback) {}