Move StringPiece into the base namespace. It is colliding

chrome/browser/extensions/extension_host.cc

 // Copyright (c) 2006-2009 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/extension_host.h"
 
 #include "app/resource_bundle.h"
 #include "base/string_util.h"
 #include "chrome/browser/browser.h"
 #include "chrome/browser/browser_list.h"
@@ skipping 133 matching lines @@
   url_ = params.url;
   if (!url_.SchemeIs(chrome::kExtensionScheme)) {
     extension_function_dispatcher_.reset(NULL);
     return;
   }
   extension_function_dispatcher_.reset(
       new ExtensionFunctionDispatcher(render_view_host_, this, url_));
 }
 
 void ExtensionHost::DidStopLoading(RenderViewHost* render_view_host) {
-  static const StringPiece toolstrip_css(
+  static const base::StringPiece toolstrip_css(
       ResourceBundle::GetSharedInstance().GetRawDataResource(
           IDR_EXTENSIONS_TOOLSTRIP_CSS));
 #if defined(TOOLKIT_VIEWS)
   ExtensionView* view = view_.get();
   if (view) {
     // TODO(erikkay) this injection should really happen in the renderer.
     // When the Jerry's view type change lands, investigate moving this there.
 
     // As a toolstrip, inject our toolstrip CSS to make it easier for toolstrips
     // to blend in with the chrome UI.
@@ skipping 188 matching lines @@
     window_id = ExtensionTabUtil::GetWindowId(
         const_cast<ExtensionHost* >(this)->GetBrowser());
   } else if (extension_host_type_ == ViewType::EXTENSION_BACKGROUND_PAGE) {
     // Background page is not attached to any browser window, so pass -1.
     window_id = -1;
   } else {
     NOTREACHED();
   }
   return window_id;
 }