Replacing the OVERRIDE with override in tools folder

tools/gn/loader.h

 // Copyright (c) 2013 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 TOOLS_GN_LOADER_H_
 #define TOOLS_GN_LOADER_H_
 
 #include <map>
 #include <set>
 
@@ skipping 66 matching lines @@
                               const BuildSettings*,
                               const SourceFile&,
                               const base::Callback<void(const ParseNode*)>&,
                               Err*)> AsyncLoadFileCallback;
 
   LoaderImpl(const BuildSettings* build_settings);
 
   // Loader implementation.
   virtual void Load(const SourceFile& file,
                     const LocationRange& origin,
-                    const Label& toolchain_name) OVERRIDE;
-  virtual void ToolchainLoaded(const Toolchain* toolchain) OVERRIDE;
-  virtual Label GetDefaultToolchain() const OVERRIDE;
+                    const Label& toolchain_name) override;
+  virtual void ToolchainLoaded(const Toolchain* toolchain) override;
+  virtual Label GetDefaultToolchain() const override;
   virtual const Settings* GetToolchainSettings(
-      const Label& label) const OVERRIDE;
+      const Label& label) const override;
 
   // Sets the message loop corresponding to the main thread. By default this
   // class will use the thread active during construction, but there is not
   // a message loop active during construction all the time.
   void set_main_loop(base::MessageLoop* loop) { main_loop_ = loop; }
 
   // The complete callback is called whenever there are no more pending loads.
   // Called on the main thread only. This may be called more than once if the
   // queue is drained, but then more stuff gets added.
   void set_complete_callback(const base::Closure& cb) {
@@ skipping 71 matching lines @@
   const BuildSettings* build_settings_;
   Label default_toolchain_label_;
 
   // Records for the build config file loads.
   // Owning pointers.
   typedef std::map<Label, ToolchainRecord*> ToolchainRecordMap;
   ToolchainRecordMap toolchain_records_;
 };
 
 #endif  // TOOLS_GN_LOADER_H_