downloads: clicking "remove" on chrome://downloads should also hide shelf item.

chrome/browser/ui/cocoa/download/download_shelf_controller.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/download/download_shelf_controller.h"
 
 #include "base/mac/bundle_locations.h"
 #include "base/strings/sys_string_conversions.h"
 #include "chrome/browser/download/download_stats.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 291 matching lines @@
 
 - (void)addDownloadItem:(DownloadItem*)downloadItem {
   DCHECK([NSThread isMainThread]);
   base::scoped_nsobject<DownloadItemController> controller(
       [[DownloadItemController alloc] initWithDownload:downloadItem
                                                  shelf:self
                                              navigator:navigator_]);
   [self add:controller.get()];
 }
 
+- (void)removeDownloadItem:(DownloadItem*)downloadItem {
+  for (NSUInteger i = 0; i < [downloadItemControllers_ count]; ++i) {
+    DownloadItemController* itemController =
+        [downloadItemControllers_ objectAtIndex:i];
+    if ([itemController download] == downloadItem) {
+      [self remove:itemController];
+      return;
+    }
+  }
+}
+
 - (void)add:(DownloadItemController*)controller {
   DCHECK([NSThread isMainThread]);
   [self cancelAutoClose];
   shouldCloseOnMouseExit_ = NO;
 
   // Insert new item at the left.
   // Adding at index 0 in NSMutableArrays is O(1).
   [downloadItemControllers_ insertObject:controller atIndex:0];
 
   [itemContainerView_ addSubview:[controller view]];
@@ skipping 182 matching lines @@
   }
 
   // Set the tracking off to create a new tracking area for the control.
   // When changing the bounds/frame on a HoverButton, the tracking isn't updated
   // correctly, it needs to be turned off and back on.
   [hoverCloseButton_ setTrackingEnabled:NO];
   [hoverCloseButton_ setFrame:bounds];
   [hoverCloseButton_ setTrackingEnabled:YES];
 }
 @end