Change the conditions on which the popup blocked animation is shown to be more reliable.

chrome/browser/cocoa/download_started_animation_mac.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.
 //
 // This file contains the Mac implementation the download animation, displayed
 // at the start of a download. The animation produces an arrow pointing
 // downwards and animates towards the bottom of the window where the new
 // download appears in the download shelf.
 
 #include "chrome/browser/download/download_started_animation.h"
@@ skipping 17 matching lines @@
 // Should be instantiated using +startAnimationWithTabContents:.
 @interface DownloadStartedAnimationMac : NSObject {
  @private
   // The observer for the TabContents we are drawing on.
   scoped_ptr<DownloadAnimationTabObserver> observer_;
   CGFloat imageWidth_;
   AnimatableImage* animation_;
 };
 
 + (void)startAnimationWithTabContents:(TabContents*)tabContents;
-// Called by our DownloadAnimationTabObserver if the tab is hidden or closed.
-- (void)animationComplete;
+
+// Called by the Observer if the tab is hidden or closed.
+- (void)closeAnimation;
 
 @end
 
 // A helper class to monitor tab hidden and closed notifications. If we receive
 // such a notification, we stop the animation.
 class DownloadAnimationTabObserver : public NotificationObserver {
  public:
   DownloadAnimationTabObserver(DownloadStartedAnimationMac* owner,
                                TabContents* tab_contents)
       : owner_(owner),
         tab_contents_(tab_contents) {
     registrar_.Add(this,
                    NotificationType::TAB_CONTENTS_HIDDEN,
                    Source<TabContents>(tab_contents_));
     registrar_.Add(this,
                    NotificationType::TAB_CONTENTS_DESTROYED,
                    Source<TabContents>(tab_contents_));
   }
 
   // Runs when a tab is hidden or destroyed. Let our owner know we should end
   // the animation.
   void Observe(NotificationType type,
                const NotificationSource& source,
                const NotificationDetails& details) {
     // This ends up deleting us.
-    [owner_ animationComplete];
+    [owner_ closeAnimation];
   }
 
  private:
   // The object we need to inform when we get a notification. Weak.
   DownloadStartedAnimationMac* owner_;
 
   // The tab we are observing. Weak.
   TabContents* tab_contents_;
 
   // Used for registering to receive notifications and automatic clean up.
@@ skipping 79 matching lines @@
 // Called when the parent window is resized.
 - (void)parentWindowChanged:(NSNotification*)notification {
   NSWindow* parentWindow = [animation_ parentWindow];
   DCHECK([[notification object] isEqual:parentWindow]);
   NSRect parentFrame = [parentWindow frame];
   NSRect frame = parentFrame;
   frame.size.width = MIN(imageWidth_, NSWidth(parentFrame));
   [animation_ setFrame:frame display:YES];
 }
 
+- (void)closeAnimation {

[Scott Hess - ex-Googler, 2010/08/31 14:29:48]

+1 for the name change, -animationComplete never quite felt comfortable.

+  [animation_ close];
+}
+
+// When the animation closes, close the parent window.

[Scott Hess - ex-Googler, 2010/08/31 14:29:48]

Either this comment is too subtle for me to understand, or it's not describing
the following code.  [I'm fine w/o the comment, given that it just duplicates
the comment when the notification is registered.]

 - (void)windowWillClose:(NSNotification*)notification {
   DCHECK([[notification object] isEqual:animation_]);
-  [self animationComplete];
-}
-
-- (void)animationComplete {
   [[animation_ parentWindow] removeChildWindow:animation_];
   [self release];
 }
 
 + (void)startAnimationWithTabContents:(TabContents*)contents {
-  // Will be deleted when the animation is complete in -animationComplete.
+  // Will be deleted when the animation window closes.
   DownloadStartedAnimationMac* controller =
       [[self alloc] initWithTabContents:contents];
   // The initializer can return nil.
   if (!controller)
     return;
 
   // The |animation_| releaes itself when done.

[Scott Hess - ex-Googler, 2010/08/31 14:29:48]

"releases", while we're in here.

   [controller->animation_ startAnimation];
 }
 
 @end
 
 void DownloadStartedAnimation::Show(TabContents* tab_contents) {
   DCHECK(tab_contents);
 
   // Will be deleted when the animation is complete.
   [DownloadStartedAnimationMac startAnimationWithTabContents:tab_contents];
 }