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 126623ff0e78cda2f2f43166018376a2bf29d2f2..7ab45015421fa5f22f2a00652ad2c215b866b2bc 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 {
 
@@ -292,13 +302,39 @@ void NativeWidgetMac::InitModalType(ui::ModalType modal_type) {
 }
 
 gfx::Rect NativeWidgetMac::GetWindowBoundsInScreen() const {
-  return gfx::ScreenRectFromNSRect([GetNativeWindow() frame]);
+  // -[NSWindow frame] doesn't update during a window drag. This is not what
+  // toolkit-views expects, so ask the window server directly.
+  //
+  // Note: Moving the window using the window server is asynchronous, and it can
+  // continue sending the frame updates (using NSWindowMovedEventType event)
+  // even after the mouse button is released.
+  NSRect frame_rect = [GetNativeWindow() frame];
+  if (bridge_->IsRunMoveLoopActive())
+    frame_rect = gfx::ScreenRectToNSRect(WindowServerFrame());
+  return gfx::ScreenRectFromNSRect(frame_rect);
+}
+
+gfx::Rect NativeWidgetMac::WindowServerFrame() const {
+  CGRect bounds = NSZeroRect;
+  CGSGetWindowBounds(_CGSDefaultConnection(), [GetNativeWindow() windowNumber],
+                     &bounds);
+  NSRect rect = ScreenRectToNSRect(gfx::Rect(bounds));
+  rect.size = [GetNativeWindow() frame].size;
+  return gfx::ScreenRectFromNSRect(rect);
 }
 
 gfx::Rect NativeWidgetMac::GetClientAreaBoundsInScreen() const {
   NSWindow* window = GetNativeWindow();
-  return gfx::ScreenRectFromNSRect(
-      [window contentRectForFrameRect:[window frame]]);
+  NSRect frame_rect = [window frame];
+  // -[NSWindow frame] doesn't update during a window drag. This is not what
+  // toolkit-views expects, so ask the window server directly.
+  //
+  // Note: Moving the window using the window server is asynchronous, and it can
+  // continue sending the frame updates (using NSWindowMovedEventType event)
+  // even after the mouse button is released.
+  if (bridge_->IsRunMoveLoopActive())
+    frame_rect = gfx::ScreenRectToNSRect(WindowServerFrame());
+  return gfx::ScreenRectFromNSRect([window contentRectForFrameRect:frame_rect]);
 }
 
 gfx::Rect NativeWidgetMac::GetRestoredBounds() const {
@@ -546,12 +582,15 @@ 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) {