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 a8ac8a6843dd732fa4af0ba4a819bb8421760f9f..db8dcd69334efbff03bcc2f9810993a0a678a444 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -241,6 +241,9 @@ RenderWidgetHostImpl::RenderWidgetHostImpl(RenderWidgetHostDelegate* delegate,
       base::Bind(&RenderWidgetHostImpl::ClearDisplayedGraphics,
                  weak_factory_.GetWeakPtr())));
 
+  for (size_t i = 0; i < arraysize(index_map_); ++i)
+    index_map_[i] = -1;
+
   delegate_->RenderWidgetCreated(this);
 }
 
@@ -1700,12 +1703,63 @@ void RenderWidgetHostImpl::OnQueueSyntheticGesture(
     return;
   }
 
+  if (gesture_packet.gesture_params()->GetGestureType() ==
+      SyntheticGestureParams::POINTER_ACTION) {
+    QueueSyntheticPointerAction(
+        *SyntheticPointerActionParams::Cast(gesture_packet.gesture_params()));
+    return;
+  }
+
   QueueSyntheticGesture(
         SyntheticGesture::Create(*gesture_packet.gesture_params()),
         base::Bind(&RenderWidgetHostImpl::OnSyntheticGestureCompleted,
                    weak_factory_.GetWeakPtr()));
 }
 
+void RenderWidgetHostImpl::QueueSyntheticPointerAction(

[tdresser, 2016/04/18 15:24:39]

We'd prefer to have this logic encapsulated within the
SyntheticGestureController, if possible.

Does this need to live in RWHI?

[lanwei, 2016/04/19 19:05:32]

No, you are right, I will move this part related to queuing synthetic pointer
actions to SyntheticGestureController.

+    const SyntheticPointerActionParams& gesture_params) {
+  if (gesture_params.pointer_action_type() ==
+      SyntheticPointerActionParams::PointerActionType::PROCESS) {
+    if (!synthetic_gesture_controller_ && view_) {
+      synthetic_gesture_controller_.reset(new SyntheticGestureController(
+          view_->CreateSyntheticGestureTarget()));
+    }
+    if (synthetic_gesture_controller_) {
+      // Todo(lanwei@): Should check if type is pointer, make sure
+      // synthetic_pointer_ is not null.
+      DCHECK(gesture_params.pointer_action_type() !=
+             SyntheticPointerActionParams::PointerActionType::NOT_INITIALIZED);
+
+      if (!synthetic_pointer_)
+        SetSyntheticPointer(gesture_params);
+
+      QueueSyntheticGesture(
+          std::unique_ptr<SyntheticGesture>(new SyntheticPointerAction(
+              action_param_list_, synthetic_pointer_.get(), index_map_)),
+          base::Bind(&RenderWidgetHostImpl::OnSyntheticPointerActionCompleted,
+                     weak_factory_.GetWeakPtr()));
+    }
+    action_param_list_.clear();
+    return;
+  }
+
+  action_param_list_.push_back(gesture_params);
+}
+
+void RenderWidgetHostImpl::SetSyntheticPointer(
+    const SyntheticPointerActionParams& gesture_params) {
+  SyntheticGestureParams::GestureSourceType gesture_source_type =
+      gesture_params.gesture_source_type;
+  if (gesture_source_type == SyntheticGestureParams::DEFAULT_INPUT) {
+    if (synthetic_gesture_controller_) {
+      gesture_source_type =
+          synthetic_gesture_controller_->GetDefaultSyntheticGestureSourceType();
+      DCHECK_NE(gesture_source_type, SyntheticGestureParams::DEFAULT_INPUT);
+      synthetic_pointer_ = SyntheticPointer::Create(gesture_source_type);
+    }
+  }
+}
+
 void RenderWidgetHostImpl::OnSetCursor(const WebCursor& cursor) {
   SetCursor(cursor);
 }
@@ -1962,6 +2016,13 @@ void RenderWidgetHostImpl::OnUnexpectedEventAck(UnexpectedEventAckType type) {
 void RenderWidgetHostImpl::OnSyntheticGestureCompleted(
     SyntheticGesture::Result result) {
   Send(new InputMsg_SyntheticGestureCompleted(GetRoutingID()));
+  synthetic_pointer_.reset(nullptr);
+  ;
+}
+
+void RenderWidgetHostImpl::OnSyntheticPointerActionCompleted(
+    SyntheticGesture::Result result) {
+  // Do nothing
 }
 
 bool RenderWidgetHostImpl::ShouldDropInputEvents() const {