Make SyntheticPointerAction to flush the pointer action sequence

content/browser/renderer_host/input/synthetic_mouse_driver.cc

Index: content/browser/renderer_host/input/synthetic_mouse_driver.cc
diff --git a/content/browser/renderer_host/input/synthetic_mouse_driver.cc b/content/browser/renderer_host/input/synthetic_mouse_driver.cc
index 82dcbdd8a413df55d939127dc47de124f90d9822..32887e0dd081ee4a8b192819e13f9c91a1147713 100644
--- a/content/browser/renderer_host/input/synthetic_mouse_driver.cc
+++ b/content/browser/renderer_host/input/synthetic_mouse_driver.cc
@@ -18,11 +18,11 @@ void SyntheticMouseDriver::DispatchEvent(SyntheticGestureTarget* target,
   target->DispatchInputEventToPlatform(mouse_event_);
 }
 
-int SyntheticMouseDriver::Press(float x, float y) {
+void SyntheticMouseDriver::Press(float x, float y, int index) {
+  DCHECK_EQ(index, 0);

[samuong, 2016/12/20 05:13:26]

is this because only one synthetic mouse pointer is supported? is this
documented anywhere?

[lanwei, 2016/12/20 18:51:47]

Yes, because there is just one mouse cursor, supporting more than one mouses
does not have any point.
I will update the doc to state this. Also we only support one source type in one
sequence right now. Will support multi-input later. I will also include this in
the doc.

   mouse_event_ = SyntheticWebMouseEventBuilder::Build(
       blink::WebInputEvent::MouseDown, x, y, 0);
   mouse_event_.clickCount = 1;
-  return 0;
 }
 
 void SyntheticMouseDriver::Move(float x, float y, int index) {
@@ -44,9 +44,7 @@ void SyntheticMouseDriver::Release(int index) {
 
 bool SyntheticMouseDriver::UserInputCheck(
     const SyntheticPointerActionParams& params) const {
-  if (params.gesture_source_type != SyntheticGestureParams::MOUSE_INPUT)
-    return false;
-
+  DCHECK_EQ(params.index(), 0);
   if (params.pointer_action_type() ==
       SyntheticPointerActionParams::PointerActionType::NOT_INITIALIZED) {
     return false;