Prepare SyntheticPointerAction to handle touch actions for multiple fingers

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 ddd9ebaa1c6b72f3924cc1e20c85aa5f902e3a21..90dd7ff1a0e593fc8ed860216d27ac9a7eb58722 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -1166,6 +1166,19 @@ void RenderWidgetHostImpl::QueueSyntheticGesture(
   }
 }
 
+void RenderWidgetHostImpl::QueueSyntheticPointerAction(
+    const SyntheticPointerActionParams& gesture_params,
+    const base::Callback<void(SyntheticGesture::Result)>& on_complete) {
+  if (!synthetic_gesture_controller_ && view_) {
+    synthetic_gesture_controller_.reset(
+        new SyntheticGestureController(view_->CreateSyntheticGestureTarget()));
+  }
+  if (synthetic_gesture_controller_) {

[tdresser, 2016/05/31 13:44:26]

Should this ever run if !view_?

It might be easier to write as:

if (!view_)
  return;

if (!synthetic_gesture_controller_)
  sgc.reset(...);

sgc->Queue...

[lanwei, 2016/06/02 13:26:27]

I feel if the synthetic_gesture_controller is not null, but view is null then
if (!view_)
   return; 
will be skip synthetic_gesture_controller_->QueueSyntheticPointerAction.

[tdresser, 2016/06/02 13:39:24]

Is there ever a case where the controller is non-null but the view is null?

+    synthetic_gesture_controller_->QueueSyntheticPointerAction(gesture_params,
+                                                               on_complete);
+  }
+}
+
 void RenderWidgetHostImpl::SetCursor(const WebCursor& cursor) {
   if (!view_)
     return;
@@ -1689,6 +1702,15 @@ void RenderWidgetHostImpl::OnQueueSyntheticGesture(
     return;
   }
 
+  if (gesture_packet.gesture_params()->GetGestureType() ==
+      SyntheticGestureParams::POINTER_ACTION) {
+    QueueSyntheticPointerAction(
+        *SyntheticPointerActionParams::Cast(gesture_packet.gesture_params()),
+        base::Bind(&RenderWidgetHostImpl::OnSyntheticPointerActionCompleted,
+                   weak_factory_.GetWeakPtr()));
+    return;
+  }
+
   QueueSyntheticGesture(
         SyntheticGesture::Create(*gesture_packet.gesture_params()),
         base::Bind(&RenderWidgetHostImpl::OnSyntheticGestureCompleted,
@@ -1953,6 +1975,15 @@ void RenderWidgetHostImpl::OnSyntheticGestureCompleted(
   Send(new InputMsg_SyntheticGestureCompleted(GetRoutingID()));
 }
 
+void RenderWidgetHostImpl::OnSyntheticPointerActionCompleted(
+    SyntheticGesture::Result result) {
+  if (result == SyntheticGesture::POINTER_ACTION_FINISHED) {
+    if (synthetic_gesture_controller_)
+      synthetic_gesture_controller_->ResetSyntheticPointer();
+    Send(new InputMsg_SyntheticGestureCompleted(GetRoutingID()));
+  }
+}
+
 bool RenderWidgetHostImpl::ShouldDropInputEvents() const {
   return ignore_input_events_ || process_->IgnoreInputEvents() || !delegate_;
 }