Enable sending gesture events from layout tests

content/shell/renderer/test_runner/event_sender.cc

Index: content/shell/renderer/test_runner/event_sender.cc
diff --git a/content/shell/renderer/test_runner/event_sender.cc b/content/shell/renderer/test_runner/event_sender.cc
index b113fb7077b2c948cece87a371a7dc2435a93f78..469406f8e25b1cb56be9de5271c3de15879d1846 100644
--- a/content/shell/renderer/test_runner/event_sender.cc
+++ b/content/shell/renderer/test_runner/event_sender.cc
@@ -396,6 +396,9 @@ class EventSenderBindings : public gin::Wrappable<EventSenderBindings> {
   void GestureScrollBegin(gin::Arguments* args);
   void GestureScrollEnd(gin::Arguments* args);
   void GestureScrollUpdate(gin::Arguments* args);
+  void GesturePinchBegin(gin::Arguments* args);
+  void GesturePinchEnd(gin::Arguments* args);
+  void GesturePinchUpdate(gin::Arguments* args);
   void GestureTap(gin::Arguments* args);
   void GestureTapDown(gin::Arguments* args);
   void GestureShowPress(gin::Arguments* args);
@@ -526,6 +529,9 @@ EventSenderBindings::GetObjectTemplateBuilder(v8::Isolate* isolate) {
       .SetMethod("gestureScrollEnd", &EventSenderBindings::GestureScrollEnd)
       .SetMethod("gestureScrollUpdate",
                  &EventSenderBindings::GestureScrollUpdate)
+      .SetMethod("gesturePinchBegin", &EventSenderBindings::GesturePinchBegin)
+      .SetMethod("gesturePinchEnd", &EventSenderBindings::GesturePinchEnd)
+      .SetMethod("gesturePinchUpdate", &EventSenderBindings::GesturePinchUpdate)
       .SetMethod("gestureTap", &EventSenderBindings::GestureTap)
       .SetMethod("gestureTapDown", &EventSenderBindings::GestureTapDown)
       .SetMethod("gestureShowPress", &EventSenderBindings::GestureShowPress)
@@ -785,6 +791,21 @@ void EventSenderBindings::GestureScrollUpdate(gin::Arguments* args) {
     sender_->GestureScrollUpdate(args);
 }
 
+void EventSenderBindings::GesturePinchBegin(gin::Arguments* args) {
+  if (sender_)
+    sender_->GesturePinchBegin(args);
+}
+
+void EventSenderBindings::GesturePinchEnd(gin::Arguments* args) {
+  if (sender_)
+    sender_->GesturePinchEnd(args);
+}
+
+void EventSenderBindings::GesturePinchUpdate(gin::Arguments* args) {
+  if (sender_)
+    sender_->GesturePinchUpdate(args);
+}
+
 void EventSenderBindings::GestureTap(gin::Arguments* args) {
   if (sender_)
     sender_->GestureTap(args);
@@ -1749,6 +1770,18 @@ void EventSender::GestureScrollUpdate(gin::Arguments* args) {
   GestureEvent(WebInputEvent::GestureScrollUpdate, args);
 }
 
+void EventSender::GesturePinchBegin(gin::Arguments* args) {
+  GestureEvent(WebInputEvent::GesturePinchBegin, args);
+}
+
+void EventSender::GesturePinchEnd(gin::Arguments* args) {
+  GestureEvent(WebInputEvent::GesturePinchEnd, args);
+}
+
+void EventSender::GesturePinchUpdate(gin::Arguments* args) {
+  GestureEvent(WebInputEvent::GesturePinchUpdate, args);
+}
+
 void EventSender::GestureTap(gin::Arguments* args) {
   GestureEvent(WebInputEvent::GestureTap, args);
 }
@@ -1994,6 +2027,27 @@ void EventSender::GestureEvent(WebInputEvent::Type type,
       event.x = current_gesture_location_.x;
       event.y = current_gesture_location_.y;
       break;
+    case WebInputEvent::GesturePinchBegin:

[Rick Byers, 2015/01/29 20:43:27]

don't you need a way to specify the source device (touchpad / touchscreen)? 
Looks like we are probably getting away without this for GestureScroll events -
probably because only touchscreen scroll events ever make it to blink so blink
might not even check the source (but ideally we'd be explicitly initializing the
sourceDevice for all GestureScroll events to TouchScreen).

If you don't actually need to differentiate them in your code or have just a
DCHECK to verify it's only touchpad (sorry been swamped today - haven't looked
yet), then it's find to just hardcode to one value here.  Otherwise you may need
to take an extra param to set the sourceDevice.

[ccameron, 2015/01/29 21:30:40]

Well, I'll want to test that touchscreen events don't produce synthetic events,
too, so I'll need a type.

I had empirically noticed that the type was always touchpad ... BUT it turns out
that was just undefined behavior. I've updated this so that all gestures are by
default touchpad, but if the first argument is a string, that string can be
"touchpad" or "touchscreen" to differentiate the two.

+    case WebInputEvent::GesturePinchEnd:
+      current_gesture_location_ = WebPoint(x, y);
+      event.x = current_gesture_location_.x;
+      event.y = current_gesture_location_.y;
+      break;
+    case WebInputEvent::GesturePinchUpdate:
+    {
+      float scale = 1;
+      if (!args->PeekNext().IsEmpty()) {
+        if (!args->GetNext(&scale)) {
+          args->ThrowError();
+          return;
+        }
+      }
+      event.data.pinchUpdate.scale = scale;
+      current_gesture_location_ = WebPoint(x, y);
+      event.x = current_gesture_location_.x;
+      event.y = current_gesture_location_.y;
+      break;
+    }
     case WebInputEvent::GestureTap:
     {
       float tap_count = 1;