Make SyntheticPointerAction to flush the pointer action sequence

content/browser/renderer_host/render_widget_host_impl.cc

Index: content/browser/renderer_host/render_widget_host_impl.cc
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc
index fde38b4ccd86bfdf1b97442ac82f4ee70f496363..442c8b5bed89e30e66f0779279f4cb5380b6f2bc 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -1184,10 +1184,7 @@ void RenderWidgetHostImpl::ForwardKeyboardEvent(
 void RenderWidgetHostImpl::QueueSyntheticGesture(
     std::unique_ptr<SyntheticGesture> synthetic_gesture,
     const base::Callback<void(SyntheticGesture::Result)>& on_complete) {
-  if (!synthetic_gesture_controller_ && view_) {
-    synthetic_gesture_controller_.reset(
-        new SyntheticGestureController(view_->CreateSyntheticGestureTarget()));
-  }
+  SetSyntheticGestureController();

[tdresser, 2016/10/26 18:28:40]

We call SetSyntheticGestureController before we ever call QueueSyntheticGesture,
don't we?

Is this needed?

[lanwei, 2016/10/30 23:23:13]

Yes, there are some other places which also call this method without calling
RenderWidgetHostImpl::OnQueueSyntheticGesture first, such as in
InputHandler::SynthesizeTapGesture 
https://codesearch.chromium.org/chromium/src/content/browser/devtools/protoco...
so we do need set SyntheticGestureControlle here.

   if (synthetic_gesture_controller_) {
     synthetic_gesture_controller_->QueueSyntheticGesture(
         std::move(synthetic_gesture), on_complete);
@@ -1746,10 +1743,23 @@ void RenderWidgetHostImpl::OnQueueSyntheticGesture(
     return;
   }
 
+  SetSyntheticGestureController();
+  std::unique_ptr<SyntheticGesture> synthetic_gesture;
+  const SyntheticGestureParams* gesture_params =
+      gesture_packet.gesture_params();
+  if (gesture_params->GetGestureType() ==
+      SyntheticGestureParams::POINTER_ACTION_LIST) {
+    synthetic_gesture =
+        synthetic_gesture_controller_->CreateSyntheticPointerAction(
+            *SyntheticPointerActionListParams::Cast(gesture_params));
+  } else {
+    synthetic_gesture = SyntheticGesture::Create(*gesture_params);
+  }
+
   QueueSyntheticGesture(
-        SyntheticGesture::Create(*gesture_packet.gesture_params()),
-        base::Bind(&RenderWidgetHostImpl::OnSyntheticGestureCompleted,
-                   weak_factory_.GetWeakPtr()));
+      std::move(synthetic_gesture),
+      base::Bind(&RenderWidgetHostImpl::OnSyntheticGestureCompleted,
+                 weak_factory_.GetWeakPtr()));
 }
 
 void RenderWidgetHostImpl::OnSetCursor(const WebCursor& cursor) {
@@ -2192,6 +2202,14 @@ void RenderWidgetHostImpl::OnSnapshotDataReceivedAsync(
     OnSnapshotDataReceived(snapshot_id, NULL, 0);
 }
 
+void RenderWidgetHostImpl::SetSyntheticGestureController() {

[tdresser, 2016/10/26 18:28:40]

This method is confusing. Should it be called CreateSyntheticGestureController?
You aren't setting it to anything in particular.

If so, we might want to DCHECK that this hasn't been called yet.

[lanwei, 2016/10/30 23:23:13]

Done.

+  if (synthetic_gesture_controller_ || !view_)
+    return;
+
+  synthetic_gesture_controller_.reset(
+      new SyntheticGestureController(view_->CreateSyntheticGestureTarget()));
+}
+
 // static
 void RenderWidgetHostImpl::CompositorFrameDrawn(
     const std::vector<ui::LatencyInfo>& latency_info) {