[Extensions Toolbar Mac] Implement drag-and-drop for the overflow menu

chrome/browser/ui/cocoa/extensions/browser_action_button.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 "chrome/browser/ui/cocoa/extensions/browser_action_button.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/logging.h"
@@ skipping 202 matching lines @@
     // same point along the button's x axis, and we avoid a "jump" when first
     // starting to drag.
     dragStartPoint_ = [self convertPoint:eventPoint fromView:nil];
 
     isBeingDragged_ = YES;
   }
 
   NSRect buttonFrame = [self frame];
   // The desired x is the current mouse point, minus the original offset of the
   // mouse into the button.
-  CGFloat desiredX = [[self superview] convertPoint:eventPoint fromView:nil].x -
-      dragStartPoint_.x;
+  NSPoint localPoint = [[self superview] convertPoint:eventPoint fromView:nil];
+  CGFloat desiredX = localPoint.x - dragStartPoint_.x;
   // Clamp the button to be within its superview along the X-axis.
   NSRect containerBounds = [[self superview] bounds];
   desiredX = std::min(std::max(NSMinX(containerBounds), desiredX),
                       NSMaxX(containerBounds) - NSWidth(buttonFrame));
+  buttonFrame.origin.x = desiredX;
 
-  buttonFrame.origin.x = desiredX;
+  // If the button is in the overflow menu, it could move along the y-axis, too.
+  if ([browserActionsController_ isOverflow]) {
+    CGFloat desiredY = localPoint.y - dragStartPoint_.y;
+    desiredY = std::min(std::max(NSMinY(containerBounds), desiredY),
+                        NSMaxY(containerBounds) - NSHeight(buttonFrame));
+    buttonFrame.origin.y = desiredY;
+  }
+
   [self setFrame:buttonFrame];
   [self setNeedsDisplay:YES];
   [[NSNotificationCenter defaultCenter]
       postNotificationName:kBrowserActionButtonDraggingNotification
       object:self];
 }
 
 - (void)mouseUp:(NSEvent*)theEvent {
   dragCouldStart_ = NO;
   // There are non-drag cases where a mouseUp: may happen
@@ skipping 163 matching lines @@
 - (ui::ThemeProvider*)themeProviderForWindow:(NSWindow*)window {
   ui::ThemeProvider* themeProvider = [window themeProvider];
   if (!themeProvider)
     themeProvider =
         [[browserActionsController_ browser]->window()->GetNativeWindow()
             themeProvider];
   return themeProvider;
 }
 
 @end