MacViews: Add native drop shadow to dialogs on OSX < 10.10.

ui/views/widget/native_widget_mac.mm

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/widget/native_widget_mac.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/mac/foundation_util.h"
 #include "base/mac/scoped_nsobject.h"
@@ skipping 484 matching lines @@
 
 void NativeWidgetMac::RunShellDrag(View* view,
                                    const ui::OSExchangeData& data,
                                    const gfx::Point& location,
                                    int operation,
                                    ui::DragDropTypes::DragEventSource source) {
   NOTIMPLEMENTED();
 }
 
 void NativeWidgetMac::SchedulePaintInRect(const gfx::Rect& rect) {
-  // TODO(tapted): This should use setNeedsDisplayInRect:, once the coordinate
-  // system of |rect| has been converted.
-  [GetNativeView() setNeedsDisplay:YES];
+  // |rect| is relative to coordinate system of the window.
+  NSRect window_frame = [GetNativeWindow() frame];
+  // Convert rect to AppKit coordinate system.
+  NSRect target_rect_window =
+      NSMakeRect(rect.x(), window_frame.size.height - rect.y() - rect.height(),
+                 rect.width(), rect.height());
+  // Now target_rect is in the Appkit window's coordinate system. Convert it to
+  // native view's coordinate system.
+  NSView* native_view = GetNativeView();
+  NSRect target_rect_view =
+      [native_view convertRect:target_rect_window fromView:nil];
+  [native_view setNeedsDisplayInRect:target_rect_view];
   if (bridge_ && bridge_->layer())
     bridge_->layer()->SchedulePaint(rect);
 }
 
 void NativeWidgetMac::SetCursor(gfx::NativeCursor cursor) {
   if (bridge_)
     bridge_->SetCursor(cursor);
 }
 
 bool NativeWidgetMac::IsMouseEventsEnabled() const {
@@ skipping 203 matching lines @@
   [[ViewsNSWindowCloseAnimator alloc] initWithWindow:window];
 }
 
 - (void)animationDidEnd:(NSAnimation*)animation {
   [window_ close];
   [animation_ setDelegate:nil];
   [self release];
 }
 
 @end