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

chrome/browser/cocoa/download_item_button.h

Index: chrome/browser/cocoa/download_item_button.h
diff --git a/chrome/browser/cocoa/download_item_button.h b/chrome/browser/cocoa/download_item_button.h
index 5ce1a014e09ecb18aa406693e1307f8cf7567c60..b421e3bf4a41b5baebd286ca84f07b5773248fcb 100644
--- a/chrome/browser/cocoa/download_item_button.h
+++ b/chrome/browser/cocoa/download_item_button.h
@@ -7,13 +7,18 @@
 #include "base/file_path.h"
 #import "chrome/browser/cocoa/draggable_button.h"
 
-// A button that is a drag source for a file.
+@class DownloadItemController;
+
+// A button that is a drag source for a file and that displays a context menu
+// instead of firing an action when clicked in a certain area.
 @interface DownloadItemButton : DraggableButton {
  @private
   FilePath downloadPath_;
+  DownloadItemController* controller_;  // weak
 }
 
 @property(assign, nonatomic) FilePath download;
+@property(assign, nonatomic) DownloadItemController* controller;
 
 // Overridden from DraggableButton.
 - (void)beginDrag:(NSEvent*)event;