Move BenchTimer to tools as Timer

tools/timer/GpuTimer.h

-
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
-#ifndef SkBenchGpuTimer_DEFINED
-#define SkBenchGpuTimer_DEFINED
+#ifndef GpuTimer_DEFINED
+#define GpuTimer_DEFINED
 
 class SkGLContextHelper;
 
-class BenchGpuTimer {
+class GpuTimer {
 public:
-    BenchGpuTimer(const SkGLContextHelper* glctx);
-    ~BenchGpuTimer();
-    void startGpu();
-    double endGpu();
+    GpuTimer(const SkGLContextHelper*);
+    ~GpuTimer();
+    void start();
+    double end();
 private:
     unsigned fQuery;
     int fStarted;
     const SkGLContextHelper* fContext;
     bool fSupported;
 };
 
 #endif