[Autofill] (Mostly) fix Autofill popup positioning on multiple monitors.

chrome/browser/ui/cocoa/autofill/autofill_popup_view_bridge.mm

 // Copyright (c) 2012 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.
 
 #import <Cocoa/Cocoa.h>
 
 #include "chrome/browser/ui/cocoa/autofill/autofill_popup_view_bridge.h"
 
 #include "base/logging.h"
 #include "chrome/browser/ui/autofill/autofill_popup_controller.h"
@@ skipping 74 matching lines @@
 
 void AutofillPopupViewBridge::InvalidateRow(size_t row) {
   NSRect dirty_rect =
       NSRectFromCGRect(controller_->GetRowBounds(row).ToCGRect());
   [view_ setNeedsDisplayInRect:dirty_rect];
 }
 
 void AutofillPopupViewBridge::UpdateBoundsAndRedrawPopup() {
   NSRect frame = NSRectFromCGRect(controller_->popup_bounds().ToCGRect());
 
-  // Flip coordinates back into Cocoa-land.
-  // TODO(isherman): Does this agree with the controller's idea of handling
-  // multi-monitor setups correctly?
-  NSScreen* screen = [[controller_->container_view() window] screen];
-  frame.origin.y = NSHeight([screen frame]) - NSMaxY(frame);
+  // Flip coordinates back into Cocoa-land.  The controller's platform-neutral
+  // coordinate space places the origin at the top-left of the first screen,
+  // whereas Cocoa's coordinate space expects the origin to be at the
+  // bottom-left of this same screen.
+  NSScreen* screen = [[NSScreen screens] objectAtIndex:0];
+  frame.origin.y = NSMaxY([screen frame]) - NSMaxY(frame);
 
   // Leave room for the border.
   frame = NSInsetRect(frame, -kBorderWidth, -kBorderWidth);
   if (controller_->popup_bounds().y() > controller_->element_bounds().y()) {
     // Popup is below the element which initiated it.
     frame.origin.y -= kBorderWidth;
   } else {
     // Popup is above the element which initiated it.
     frame.origin.y += kBorderWidth;
   }
   if (controller_->popup_bounds().x() == controller_->element_bounds().x()) {
     // Popup is anchored to the left of the element which initiated it.
     frame.origin.x += kBorderWidth;
   } else {
     // Popup is anhored to the right of the element which initiated it.
     frame.origin.x -= kBorderWidth;
   }
 
   // TODO(isherman): The view should support scrolling if the popup gets too
   // big to fit on the screen.
   [window_ setFrame:frame display:YES];
 }
 
 AutofillPopupView* AutofillPopupView::Create(
     AutofillPopupController* controller) {
   return new AutofillPopupViewBridge(controller);
 }
 
 }  // namespace autofill