Touch emulator: clear mouse buttons modifiers on emulated touch events.

content/browser/renderer_host/input/touch_emulator.cc

Index: content/browser/renderer_host/input/touch_emulator.cc
diff --git a/content/browser/renderer_host/input/touch_emulator.cc b/content/browser/renderer_host/input/touch_emulator.cc
index cdbc77da53e43b4ef5d218b667589b96fe3d46b3..f09716a68c8e3ec8019d51afffcd99cd12dac98e 100644
--- a/content/browser/renderer_host/input/touch_emulator.cc
+++ b/content/browser/renderer_host/input/touch_emulator.cc
@@ -39,6 +39,12 @@ ui::GestureProvider::Config GetEmulatorGestureProviderConfig(
   return config;
 }
 
+int ModifiersWithoutMouseButtons(const WebInputEvent& event) {
+  const int all_buttons = WebInputEvent::LeftButtonDown |
+      WebInputEvent::MiddleButtonDown | WebInputEvent::RightButtonDown;
+  return event.modifiers & ~all_buttons;
+}
+
 // Time between two consecutive mouse moves, during which second mouse move
 // is not converted to touch.
 const double kMouseMoveDropIntervalSeconds = 5.f / 1000;
@@ -398,7 +404,7 @@ void TouchEmulator::PinchEnd(const WebGestureEvent& event) {
 
 void TouchEmulator::FillPinchEvent(const WebInputEvent& event) {
   pinch_event_.timeStampSeconds = event.timeStampSeconds;
-  pinch_event_.modifiers = event.modifiers;
+  pinch_event_.modifiers = ModifiersWithoutMouseButtons(event);
   pinch_event_.sourceDevice = blink::WebGestureDeviceTouchscreen;
   pinch_event_.x = pinch_anchor_.x();
   pinch_event_.y = pinch_anchor_.y();
@@ -407,7 +413,7 @@ void TouchEmulator::FillPinchEvent(const WebInputEvent& event) {
 void TouchEmulator::ScrollEnd(const WebGestureEvent& event) {
   WebGestureEvent scroll_event;
   scroll_event.timeStampSeconds = event.timeStampSeconds;
-  scroll_event.modifiers = event.modifiers;
+  scroll_event.modifiers = ModifiersWithoutMouseButtons(event);
   scroll_event.sourceDevice = blink::WebGestureDeviceTouchscreen;
   scroll_event.type = WebInputEvent::GestureScrollEnd;
   client_->ForwardEmulatedGestureEvent(scroll_event);
@@ -430,7 +436,7 @@ void TouchEmulator::FillTouchEventAndPoint(const WebMouseEvent& mouse_event) {
       NOTREACHED() << "Invalid event for touch emulation: " << mouse_event.type;
   }
   touch_event_.touchesLength = 1;
-  touch_event_.modifiers = mouse_event.modifiers;
+  touch_event_.modifiers = ModifiersWithoutMouseButtons(mouse_event);
   WebTouchEventTraits::ResetTypeAndTouchStates(
       eventType, mouse_event.timeStampSeconds, &touch_event_);