Support gesture events in WebFrameWidgetImpl.

Source/web/WebFrameWidgetImpl.cpp

Index: Source/web/WebFrameWidgetImpl.cpp
diff --git a/Source/web/WebFrameWidgetImpl.cpp b/Source/web/WebFrameWidgetImpl.cpp
index bfd1d4968049e1320aaf4c1b00cc30b028791228..9f63725c766a238ffb4bf3503bca08ac163c9004 100644
--- a/Source/web/WebFrameWidgetImpl.cpp
+++ b/Source/web/WebFrameWidgetImpl.cpp
@@ -722,8 +722,33 @@ bool WebFrameWidgetImpl::handleMouseWheel(LocalFrame& mainFrame, const WebMouseW
 
 bool WebFrameWidgetImpl::handleGestureEvent(const WebGestureEvent& event)
 {
-    // FIXME: Add gesture support.
-    return false;
+    bool eventSwallowed = false;
+    bool eventCancelled = false;
+    switch (event.type) {
+    case WebInputEvent::GestureScrollBegin:
+    case WebInputEvent::GestureScrollEnd:
+    case WebInputEvent::GestureScrollUpdate:
+    case WebInputEvent::GestureTap:
+    case WebInputEvent::GestureTapUnconfirmed:
+    case WebInputEvent::GestureTapDown:
+    case WebInputEvent::GestureShowPress:
+    case WebInputEvent::GestureTapCancel:
+    case WebInputEvent::GestureDoubleTap:
+    case WebInputEvent::GestureTwoFingerTap:
+    case WebInputEvent::GestureLongPress:
+    case WebInputEvent::GestureLongTap:
+        break;
+    case WebInputEvent::GestureFlingStart:
+    case WebInputEvent::GestureFlingCancel:
+        m_client->didHandleGestureEvent(event, eventCancelled);
+        return false;
+    default:
+        ASSERT_NOT_REACHED();
+    }
+    const LocalFrame* frame = m_localRoot->frame();

[dcheng, 2015/08/31 16:51:20]

Nit: const here looks weird: handling a gesture event doesn't really seem like
an action that wouldn't change any state on the frame.

[Peng, 2015/08/31 17:34:57]

Done.

+    eventSwallowed = frame->eventHandler().handleGestureEvent(PlatformGestureEventBuilder(frame->view(), event));
+    m_client->didHandleGestureEvent(event, eventCancelled);
+    return eventSwallowed;
 }
 
 bool WebFrameWidgetImpl::handleKeyEvent(const WebKeyboardEvent& event)