[Extensions] rm unnecessary GetRawDataResource().as_string() to reduce string copy.

chrome/browser/ui/webui/extensions/extension_icon_source.cc

Index: chrome/browser/ui/webui/extensions/extension_icon_source.cc
diff --git a/chrome/browser/ui/webui/extensions/extension_icon_source.cc b/chrome/browser/ui/webui/extensions/extension_icon_source.cc
index 2230e3c478be626bc7da6da9e1787ea323cbcd69..ac6c03f417469500b92a3192620c980b26120b1c 100644
--- a/chrome/browser/ui/webui/extensions/extension_icon_source.cc
+++ b/chrome/browser/ui/webui/extensions/extension_icon_source.cc
@@ -97,9 +97,9 @@ GURL ExtensionIconSource::GetIconURL(const Extension* extension,
 
 // static
 SkBitmap* ExtensionIconSource::LoadImageByResourceId(int resource_id) {
-  std::string contents = ResourceBundle::GetSharedInstance()
-      .GetRawDataResourceForScale(resource_id,
-                                  ui::SCALE_FACTOR_100P).as_string();
+  base::StringPiece contents =
+      ResourceBundle::GetSharedInstance().GetRawDataResourceForScale(
+          resource_id, ui::SCALE_FACTOR_100P);
 
   // Convert and return it.
   const unsigned char* data =