PageActions can now specify multiple icons and switch between them...

chrome/browser/extensions/extensions_service.cc

 // Copyright (c) 2009 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/extensions/extensions_service.h"
 
 #include "app/l10n_util.h"
 #include "base/command_line.h"
 #include "base/crypto/signature_verifier.h"
 #include "base/file_util.h"
@@ skipping 734 matching lines @@
           WideToUTF8(plugin.path.ToWStringHack()).c_str()));
       return NULL;
     }
   }
 
   // Validate icon location for page actions.
   const PageActionMap& page_actions = extension->page_actions();
   for (PageActionMap::const_iterator i(page_actions.begin());
        i != page_actions.end(); ++i) {
     PageAction* page_action = i->second;
-    FilePath path = page_action->icon_path();
-    if (!file_util::PathExists(path)) {
-      ReportExtensionLoadError(extension_path,
-          StringPrintf("Could not load icon '%s' for page action.",
-          WideToUTF8(path.ToWStringHack()).c_str()));
-      return NULL;
+    const std::vector<FilePath>& icon_paths = page_action->icon_paths();
+    for (std::vector<FilePath>::const_iterator iter = icon_paths.begin();
+         iter != icon_paths.end(); ++iter) {
+      FilePath path = *iter;
+      if (!file_util::PathExists(path)) {
+        ReportExtensionLoadError(extension_path,
+            StringPrintf("Could not load icon '%s' for page action.",
+            WideToUTF8(path.ToWStringHack()).c_str()));
+        return NULL;
+      }
     }
   }
 
   return extension.release();
 }
 
 void ExtensionsServiceBackend::ReportExtensionLoadError(
     const FilePath& extension_path, const std::string &error) {
   // TODO(port): note that this isn't guaranteed to work properly on Linux.
   std::string path_str = WideToASCII(extension_path.ToWStringHack());
@@ skipping 603 matching lines @@
   Extension::InstallType install_type =
       CompareToInstalledVersion(id, version->GetString(), &current_version);
 
   if (install_type == Extension::DOWNGRADE)
     return false;
 
   return (install_type == Extension::UPGRADE ||
           install_type == Extension::NEW_INSTALL ||
           NeedsReinstall(id, current_version));
 }