Plumb smooth scrolling in Chromium compositor

content/renderer/input/input_handler_proxy.cc

Index: content/renderer/input/input_handler_proxy.cc
diff --git a/content/renderer/input/input_handler_proxy.cc b/content/renderer/input/input_handler_proxy.cc
index 232d8b7baf0528718f311b80e80f1d6a53620035..6ff4900d630bef5c52b34d0f854027cb13b77f90 100644
--- a/content/renderer/input/input_handler_proxy.cc
+++ b/content/renderer/input/input_handler_proxy.cc
@@ -229,6 +229,27 @@ InputHandlerProxy::HandleInputEventWithLatencyInfo(
   return disposition;
 }
 
+blink::WebGestureCurve* InputHandlerProxy::CreateAnimationCurve(
+    const blink::WebGestureEvent& gesture_event) {
+  blink::WebGestureCurve* fling_curve;
+  if (gesture_event.data.flingStart.isSmoothScroll) {
+    const float start_x = gesture_event.x;
+    const float start_y = gesture_event.y;
+    const float dx = gesture_event.data.flingStart.dx;
+    const float dy = gesture_event.data.flingStart.dy;
+    const long duration_ms = gesture_event.data.flingStart.durationMs;
+    fling_curve = client_->CreateSmoothScrollAnimationCurve(
+        gesture_event.sourceDevice, start_x, start_y, dx, dy, duration_ms);
+  } else {
+    const float vx = gesture_event.data.flingStart.velocityX;
+    const float vy = gesture_event.data.flingStart.velocityY;
+    fling_curve = client_->CreateFlingAnimationCurve(
+        gesture_event.sourceDevice, WebFloatPoint(vx, vy), blink::WebSize());
+  }
+
+  return fling_curve;
+}
+
 InputHandlerProxy::EventDisposition InputHandlerProxy::HandleInputEvent(
     const WebInputEvent& event) {
   DCHECK(input_handler_);
@@ -521,10 +542,9 @@ InputHandlerProxy::EventDisposition InputHandlerProxy::HandleGestureFlingStart(
       const float vy = gesture_event.data.flingStart.velocityY;
       current_fling_velocity_ = gfx::Vector2dF(vx, vy);
       DCHECK(!current_fling_velocity_.IsZero());
-      fling_curve_.reset(client_->CreateFlingAnimationCurve(
-          gesture_event.sourceDevice,
-          WebFloatPoint(vx, vy),
-          blink::WebSize()));
+
+      fling_curve_.reset(CreateAnimationCurve(gesture_event));
+
       disallow_horizontal_fling_scroll_ = !vx;
       disallow_vertical_fling_scroll_ = !vy;
       TRACE_EVENT_ASYNC_BEGIN2("input",
@@ -696,10 +716,7 @@ bool InputHandlerProxy::FilterInputEventForFlingBoosting(
       disallow_horizontal_fling_scroll_ = !velocity.x;
       disallow_vertical_fling_scroll_ = !velocity.y;
       last_fling_boost_event_ = WebGestureEvent();
-      fling_curve_.reset(client_->CreateFlingAnimationCurve(
-          gesture_event.sourceDevice,
-          velocity,
-          blink::WebSize()));
+      fling_curve_.reset(CreateAnimationCurve(gesture_event));
       fling_parameters_.startTime = gesture_event.timeStampSeconds;
       fling_parameters_.delta = velocity;
       fling_parameters_.point = WebPoint(gesture_event.x, gesture_event.y);