Drag-and-drop: dragSourceEndedAt, dragSourceSystemDragEnded

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 690331e23628433aa35e909b0a2b6a2d7fd5cb3d..ecdae1a4de37ee0f6749dbc5c6685fa444b1cf44 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -631,6 +631,9 @@ bool RenderWidget::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(DragMsg_TargetDragOver, OnDragTargetDragOver)
     IPC_MESSAGE_HANDLER(DragMsg_TargetDragLeave, OnDragTargetDragLeave)
     IPC_MESSAGE_HANDLER(DragMsg_TargetDrop, OnDragTargetDrop)
+    IPC_MESSAGE_HANDLER(DragMsg_SourceEnded, OnDragSourceEnded)
+    IPC_MESSAGE_HANDLER(DragMsg_SourceSystemDragEnded,
+                        OnDragSourceSystemDragEnded)
 #if defined(OS_ANDROID)
     IPC_MESSAGE_HANDLER(InputMsg_ImeEventAck, OnImeEventAck)
     IPC_MESSAGE_HANDLER(InputMsg_RequestTextInputStateUpdate,
@@ -1706,6 +1709,17 @@ void RenderWidget::OnDragTargetDrop(const DropData& drop_data,
       screen_point, key_modifiers);
 }
 
+void RenderWidget::OnDragSourceEnded(const gfx::Point& client_point,
+                                     const gfx::Point& screen_point,
+                                     WebDragOperation op) {

[ncarter (slow), 2016/11/14 23:21:37]

RenderWidget::OnDragTargetDrop seems to defend against the !GetWebWidget() case.
Do you know why, and if so, do we need to do that here?

From looking at the code we probably don't need it -- during normal operation,
GetWebWidget() ought to be a valid pointer between Init and Close(). Init is
also where the widget becomes added to the routing map, and the widget is
removed from the routing map before Close() happens.

[paulmeyer, 2016/11/15 01:20:31]

Good catch. I believe it is actually needed. If you look at other functions (not
written by me) in this file, it seems to be possible for these messages to come
through when GetWebWdiget() is null. I will add the check. dcheng@ noticed this
as well and said that something should be fixed about this in the future, but to
leave the checks in for now.

+  static_cast<WebFrameWidget*>(GetWebWidget())->dragSourceEndedAt(
+      ConvertWindowPointToViewport(client_point), screen_point, op);
+}
+
+void RenderWidget::OnDragSourceSystemDragEnded() {
+  static_cast<WebFrameWidget*>(GetWebWidget())->dragSourceSystemDragEnded();
+}
+
 void RenderWidget::showImeIfNeeded() {
 #if defined(OS_ANDROID) || defined(USE_AURA)
   UpdateTextInputState(ShowIme::IF_NEEDED, ChangeSource::FROM_NON_IME);