Move EmptyString, kWhitespace and the BOM to base.

chrome/browser/chromeos/imageburner/burn_manager.cc

Index: chrome/browser/chromeos/imageburner/burn_manager.cc
diff --git a/chrome/browser/chromeos/imageburner/burn_manager.cc b/chrome/browser/chromeos/imageburner/burn_manager.cc
index 9dee244e987ed6bcd2c77c356154c98bd601836e..de6f7f6fbb412259a076a1f2232077c47b16a9bb 100644
--- a/chrome/browser/chromeos/imageburner/burn_manager.cc
+++ b/chrome/browser/chromeos/imageburner/burn_manager.cc
@@ -120,12 +120,12 @@ const std::string& ConfigFile::GetProperty(
       if (property != block_it->properties.end()) {
         return property->second;
       } else {
-        return EmptyString();
+        return base::EmptyString();
       }
     }
   }
 
-  return EmptyString();
+  return base::EmptyString();
 }
 
 // Check if last block has a hwid associated with it, and erase it if it