Mac: Show download item menu on mouse down instead of mouse up.

chrome/browser/cocoa/download_item_button.mm

 // Copyright (c) 2010 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/cocoa/download_item_button.h"
 
+#include "base/logging.h"
 #include "base/sys_string_conversions.h"
+#import "chrome/browser/cocoa/download_item_cell.h"
+#import "chrome/browser/cocoa/download_item_controller.h"
 
 @implementation DownloadItemButton
 
 @synthesize download = downloadPath_;
+@synthesize controller = controller_;
 
 // Overridden from DraggableButton.
 - (void)beginDrag:(NSEvent*)event {
   if (!downloadPath_.empty()) {
     NSString* filename = base::SysUTF8ToNSString(downloadPath_.value());
     [self dragFile:filename fromRect:[self bounds] slideBack:YES event:event];
   }
 }
 
+// Override to show a context menu on mouse down if clicked over the context
+// menu area.
+- (void)mouseDown:(NSEvent*)event {
+  DCHECK(controller_);
+  // Override so that we can pop up a context menu on mouse down.
+  NSCell* cell = [self cell];
+  DCHECK([cell respondsToSelector:@selector(isMouseOverButtonPart)]);
+  if ([reinterpret_cast<DownloadItemCell*>(cell) isMouseOverButtonPart]) {
+    [super mouseDown:event];
+  } else {
+    // Hold a reference to our controller in case the download completes and we
+    // represent a file that's auto-removed (e.g. a theme).
+    scoped_nsobject<DownloadItemController> ref([controller_ retain]);
+    [cell setHighlighted:YES];
+    [[self menu] setDelegate:self];
+    [NSMenu popUpContextMenu:[self menu]
+                   withEvent:[NSApp currentEvent]
+                     forView:self];
+  }
+}
+
+- (void)menuDidClose:(NSMenu*)menu {
+  [[self cell] setHighlighted:NO];
+}
+
 @end