[Extensions Toolbar] Protect against crazy bounds

chrome/browser/ui/cocoa/extensions/browser_actions_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/extensions/browser_actions_controller.h"
 
 #include <string>
 
 #include "base/strings/sys_string_conversions.h"
 #include "chrome/browser/extensions/extension_message_bubble_controller.h"
@@ skipping 565 matching lines @@
             [[self buttonAtIndex:j] viewController];
         if (other_controller == toolbar_actions[i])
           break;
         ++j;
       }
       [buttons_ exchangeObjectAtIndex:i withObjectAtIndex:j];
     }
   }
 
   [self showChevronIfNecessaryInFrame:[containerView_ frame]];
-  NSUInteger minIndex = isOverflow_ ?
-      [buttons_ count] - toolbarActionsBar_->GetIconCount() : 0;
-  NSUInteger maxIndex = isOverflow_ ?
-      [buttons_ count] : toolbarActionsBar_->GetIconCount();
+  NSUInteger startIndex = toolbarActionsBar_->GetStartIndexInBounds();
+  NSUInteger endIndex = toolbarActionsBar_->GetEndIndexInBounds();
   for (NSUInteger i = 0; i < [buttons_ count]; ++i) {
     BrowserActionButton* button = [buttons_ objectAtIndex:i];
     if ([button isBeingDragged])
       continue;
 
     [self moveButton:[buttons_ objectAtIndex:i] toIndex:i];
 
-    if (i >= minIndex && i < maxIndex) {
+    if (i >= startIndex && i < endIndex) {
       // Make sure the button is within the visible container.
       if ([button superview] != containerView_) {
         // We add the subview under the sibling views so that when it
         // "slides in", it does so under its neighbors.
         [containerView_ addSubview:button
                         positioned:NSWindowBelow
                         relativeTo:nil];
       }
       // We need to set the alpha value in case the container has resized.
       [button setAlphaValue:1.0];
@@ skipping 54 matching lines @@
 - (BOOL)updateContainerVisibility {
   BOOL hidden = [buttons_ count] == 0;
   if ([containerView_ isHidden] != hidden)
     [containerView_ setHidden:hidden];
   return !hidden;
 }
 
 - (void)updateButtonOpacity {
   for (BrowserActionButton* button in buttons_.get()) {
     NSRect buttonFrame = [button frameAfterAnimation];
+    // The button is fully in the container view, and should get full opacity.
     if (NSContainsRect([containerView_ bounds], buttonFrame)) {
       if ([button alphaValue] != 1.0)
         [button setAlphaValue:1.0];
 
       continue;
     }
-    CGFloat intersectionWidth =
-        NSWidth(NSIntersectionRect([containerView_ bounds], buttonFrame));
-    CGFloat alpha = std::max(static_cast<CGFloat>(0.0),
-                             intersectionWidth / NSWidth(buttonFrame));
+    // The button is only partially in the container view. If the user is
+    // resizing the container, we have partial alpha so the icon fades in as
+    // space is made. Otherwise, hide the icon fully.
+    CGFloat alpha = 0.0;
+    if ([containerView_ userIsResizing]) {
+      CGFloat intersectionWidth =
+          NSWidth(NSIntersectionRect([containerView_ bounds], buttonFrame));
+      alpha = std::max(static_cast<CGFloat>(0.0),
+                       intersectionWidth / NSWidth(buttonFrame));
+    }
     [button setAlphaValue:alpha];
     [button setNeedsDisplay:YES];
   }
 }
 
 - (void)updateButtonPositions {
   for (NSUInteger index = 0; index < [buttons_ count]; ++index) {
     BrowserActionButton* button = [buttons_ objectAtIndex:index];
     NSRect buttonFrame = [self frameForIndex:index];
 
@@ skipping 343 matching lines @@
 }
 
 #pragma mark -
 #pragma mark Testing Methods
 
 - (BrowserActionButton*)buttonWithIndex:(NSUInteger)index {
   return index < [buttons_ count] ? [buttons_ objectAtIndex:index] : nil;
 }
 
 @end