[Extensions Toolbar] Protect against crazy bounds

chrome/browser/ui/toolbar/toolbar_actions_model.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_TOOLBAR_TOOLBAR_ACTIONS_MODEL_H_
 #define CHROME_BROWSER_UI_TOOLBAR_TOOLBAR_ACTIONS_MODEL_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_vector.h"
 #include "base/observer_list.h"
@@ skipping 10 matching lines @@
 class PrefService;
 class Profile;
 class ToolbarActionsBar;
 class ToolbarActionViewController;
 
 namespace extensions {
 class ExtensionRegistry;
 class ExtensionSet;
 }
 
-// Model for the browser actions toolbar.
+// Model for the browser actions toolbar. This is a per-profile instance, and
+// manages the user's global preferences.
+// Each browser window will attempt to show browser actions as specified by this
+// model, but if the window is too narrow, actions may end up pushed into the
+// overflow menu on a per-window basis. Callers interested in the arrangement of
+// actions in a particular window should check that window's instance of
+// ToolbarActionsBar, which is responsible for the per-window layout.
 class ToolbarActionsModel : public extensions::ExtensionActionAPI::Observer,
                             public extensions::ExtensionRegistryObserver,
                             public KeyedService {
  public:
   // The different options for highlighting.
   enum HighlightType {
     HIGHLIGHT_NONE,
     HIGHLIGHT_INFO,
     HIGHLIGHT_WARNING,
   };
@@ skipping 74 matching lines @@
   void RemoveObserver(Observer* observer);
 
   // Moves the given action with |id|'s icon to the given |index|.
   void MoveActionIcon(const std::string& id, size_t index);
 
   // Sets the number of action icons that should be visible.
   // If count == size(), this will set the visible icon count to -1, meaning
   // "show all actions".
   void SetVisibleIconCount(size_t count);
 
+  // Note that this (and all_icons_visible()) are the global default, but are
+  // inappropriate for determining a specific window's state - for that, use
+  // the ToolbarActionsBar.
   size_t visible_icon_count() const {
     // We have guards around this because |visible_icon_count_| can be set by
     // prefs/sync, and we want to ensure that the icon count returned is within
     // bounds.
     return visible_icon_count_ == -1
                ? toolbar_items().size()
                : std::min(static_cast<size_t>(visible_icon_count_),
                           toolbar_items().size());
   }
-
   bool all_icons_visible() const {
     return visible_icon_count() == toolbar_items().size();
   }
 
   bool actions_initialized() const { return actions_initialized_; }
 
   ScopedVector<ToolbarActionViewController> CreateActions(
       Browser* browser,
       ToolbarActionsBar* bar);
 
@@ skipping 133 matching lines @@
   // For observing change of toolbar order preference by external entity (sync).
   PrefChangeRegistrar pref_change_registrar_;
   base::Closure pref_change_callback_;
 
   base::WeakPtrFactory<ToolbarActionsModel> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ToolbarActionsModel);
 };
 
 #endif  // CHROME_BROWSER_UI_TOOLBAR_TOOLBAR_ACTIONS_MODEL_H_