[Extensions Toolbar] Protect against crazy bounds

chrome/browser/ui/toolbar/toolbar_actions_bar.cc

 // Copyright 2014 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.
 
 #include "chrome/browser/ui/toolbar/toolbar_actions_bar.h"
 
 #include "base/auto_reset.h"
 #include "base/location.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 246 matching lines @@
   if (!toolbar_actions_.empty() && !suppress_layout_ &&
       model_->actions_initialized()) {
     DCHECK_LE(visible_icons, toolbar_actions_.size());
     DCHECK_EQ(model_->toolbar_items().size(), toolbar_actions_.size());
   }
 #endif
 
   return visible_icons;
 }
 
-gfx::Rect ToolbarActionsBar::GetFrameForIndex(size_t index) const {
-  size_t start_index = in_overflow_mode() ?
-      toolbar_actions_.size() - GetIconCount() : 0u;
+size_t ToolbarActionsBar::GetStartIndexInBounds() const {
+  return in_overflow_mode() ?
+      main_bar_->GetEndIndexInBounds() : 0u;

[Peter Kasting, 2015/09/15 00:13:38]

Nit: Don't add 'u' here unless the code won't compile without it; if that's the
case we'd need to either static_cast to size_t or split the return to a separate
statement, as "0u" still isn't the same type as size_t on all architectures.

[Devlin, 2015/09/15 18:22:39]

Done.

+}
+
+size_t ToolbarActionsBar::GetEndIndexInBounds() const {
+  return in_overflow_mode() ?
+      toolbar_actions_.size() : WidthToIconCount(delegate_->GetWidth());
+}
+
+bool ToolbarActionsBar::NeedsOverflow() const {
+  DCHECK(!in_overflow_mode());
+  return GetEndIndexInBounds() != toolbar_actions_.size();
+}
+
+gfx::Rect ToolbarActionsBar::GetFrameForIndex(
+    size_t index) const {
+  size_t start_index = GetStartIndexInBounds();
 
   // If the index is for an action that is before range we show (i.e., is for
   // a button that's on the main bar, and this is the overflow), send back an
   // empty rect.
   if (index < start_index)
     return gfx::Rect();
 
   size_t relative_index = index - start_index;
   int icons_per_overflow_row = platform_settings().icons_per_overflow_menu_row;
   size_t row_index = in_overflow_mode() ?
@@ skipping 427 matching lines @@
   for (ToolbarActionViewController* action : toolbar_actions_) {
     if (action->GetId() == action_id)
       return action;
   }
   return nullptr;
 }
 
 content::WebContents* ToolbarActionsBar::GetCurrentWebContents() {
   return browser_->tab_strip_model()->GetActiveWebContents();
 }