Drag-and-drop: Move startDrag out of WebView/RenderView.

third_party/WebKit/public/web/WebWidgetClient.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 15 matching lines @@
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef WebWidgetClient_h
 #define WebWidgetClient_h
 
 #include "WebNavigationPolicy.h"
 #include "public/platform/WebCommon.h"
+#include "public/platform/WebDragOperation.h"
 #include "public/platform/WebLayerTreeView.h"
 #include "public/platform/WebPoint.h"
 #include "public/platform/WebRect.h"
 #include "public/platform/WebScreenInfo.h"
 #include "public/web/WebMeaningfulLayout.h"
 #include "public/web/WebTextDirection.h"
 #include "public/web/WebTouchAction.h"
 
 namespace blink {
 
+class WebDragData;
 class WebGestureEvent;
+class WebImage;
+class WebLocalFrame;
 class WebNode;
 class WebString;
 class WebWidget;
 struct WebCursorInfo;
 struct WebFloatPoint;
 struct WebFloatRect;
 struct WebFloatSize;
 struct WebSize;
 
 class WebWidgetClient {
@@ skipping 117 matching lines @@
   // TODO(oshima): Update the comment when the migration is completed.
   virtual void convertViewportToWindow(WebRect* rect) {}
 
   // Converts the |rect| from the coordinates in native window in
   // DIP to Blink's Viewport coordinates. They're identical in
   // tradional world, but will differ when use-zoom-for-dsf feature
   // is eanbled.  TODO(oshima): Update the comment when the
   // migration is completed.
   virtual void convertWindowToViewport(WebFloatRect* rect) {}
 
+  // Called when a drag-n-drop operation should begin.
+  virtual void startDragging(WebLocalFrame*,

[dcheng, 2016/11/03 21:22:52]

Can we move this to WebFrameWidget?

[paulmeyer, 2016/11/04 19:01:18]

As we discussed offline, |frame| no longer plumbed through here.

+                             const WebDragData&,
+                             WebDragOperationsMask,
+                             const WebImage& dragImage,
+                             const WebPoint& dragImageOffset) {}
+
  protected:
   ~WebWidgetClient() {}
 };
 
 }  // namespace blink
 
 #endif