MacViews: Implement Tab Dragging

ui/views/widget/native_widget_mac.mm

Index: ui/views/widget/native_widget_mac.mm
diff --git a/ui/views/widget/native_widget_mac.mm b/ui/views/widget/native_widget_mac.mm
index f307abddba85e17fd28e663327522fdd9d25a34b..b235ca50321acb408f2fb2a6c5abf501401c2388 100644
--- a/ui/views/widget/native_widget_mac.mm
+++ b/ui/views/widget/native_widget_mac.mm
@@ -37,6 +37,16 @@
 
 @end
 
+extern "C" {
+
+typedef int32_t CGSWindow;
+typedef int32_t CGSConnection;
+CGSConnection _CGSDefaultConnection();
+OSStatus CGSGetWindowBounds(
+    CGSConnection connection, CGSWindow window, CGRect* bounds);
+
+}
+
 namespace views {
 namespace {
 
@@ -60,6 +70,20 @@ NSInteger StyleMaskForParams(const Widget::InitParams& params) {
   return NSBorderlessWindowMask;
 }
 
+// -[NSWindow frame] doesn't update during a window drag. This is not what
+// toolkit-views expects, so ask the window server directly.
+NSRect FrameIncludingDrag(NSWindow* window) {
+  CGRect bounds = NSZeroRect;
+  CGSGetWindowBounds(_CGSDefaultConnection(), [window windowNumber], &bounds);
+  NSRect rect = ScreenRectToNSRect(gfx::Rect(bounds));
+
+  // If no mouse buttons are down, there is no drag. So it should match the
+  // window frame.
+  //DCHECK([NSEvent pressedMouseButtons] == 0 ||

[tapted, 2016/03/10 11:51:19]

This DCHECK would actually fail, which surprised me. I think we actually need to
get the origin from the window server and the size from [window frame] to ensure
that the window layout is in-step, synchronously with NSEvents that cause it.
But also I think we should only use FrameIncludingDrag at all when there's a
RunMoveLoop installed -- I think using it in other places could lead to test
flakiness because of asynchronous stuff around the window server.

[themblsha, 2016/03/10 17:18:58]

Done.

+  //       NSEqualRects(rect, [window frame]));
+  return rect;
+}
+
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -201,8 +225,8 @@ void NativeWidgetMac::ViewRemoved(View* view) {
   // TODO(tapted): Something for drag and drop might be needed here in future.
   // See http://crbug.com/464581. A NOTIMPLEMENTED() here makes a lot of spam,
   // so only emit it when a drag and drop could be likely.
-  if (IsMouseButtonDown())
-    NOTIMPLEMENTED();
+  // if (IsMouseButtonDown())

[tapted, 2016/03/10 11:51:19]

nit: uncomment (sorry for the log spam - drag and drop is still in the
pipeline).

[themblsha, 2016/03/10 17:18:58]

Done.

+  //   NOTIMPLEMENTED();
 }
 
 void NativeWidgetMac::SetNativeWindowProperty(const char* name, void* value) {
@@ -296,7 +320,7 @@ gfx::Rect NativeWidgetMac::GetWindowBoundsInScreen() const {
 gfx::Rect NativeWidgetMac::GetClientAreaBoundsInScreen() const {
   NSWindow* window = GetNativeWindow();
   return gfx::ScreenRectFromNSRect(
-      [window contentRectForFrameRect:[window frame]]);
+      [window contentRectForFrameRect:FrameIncludingDrag(window)]);
 }
 
 gfx::Rect NativeWidgetMac::GetRestoredBounds() const {
@@ -548,12 +572,15 @@ Widget::MoveLoopResult NativeWidgetMac::RunMoveLoop(
     const gfx::Vector2d& drag_offset,
     Widget::MoveLoopSource source,
     Widget::MoveLoopEscapeBehavior escape_behavior) {
-  NOTIMPLEMENTED();
-  return Widget::MOVE_LOOP_CANCELED;
+  if (!bridge_)
+    return Widget::MOVE_LOOP_CANCELED;
+
+  return bridge_->RunMoveLoop(drag_offset);
 }
 
 void NativeWidgetMac::EndMoveLoop() {
-  NOTIMPLEMENTED();
+  if (bridge_)
+    bridge_->EndMoveLoop();
 }
 
 void NativeWidgetMac::SetVisibilityChangedAnimationsEnabled(bool value) {