Move BenchTimer to tools as Timer

This breaks a bunch of circular dependencies between tools and gm and bench.

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/4ed75287aed6371c6e4a41ffcc78c8a49c9810ed

CQ_EXTRA_TRYBOTS=tryserver.skia:Build-Mac10.7-Clang-Arm7-Debug-iOS-Trybot,Test-Ubuntu12-ShuttleA-GTX660-x86-Debug-Trybot
R=tfarina@chromium.org, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/344213003
diff --git a/bench/benchmain.cpp b/bench/benchmain.cpp
index 6b3f587..5c3b790 100644
--- a/bench/benchmain.cpp
+++ b/bench/benchmain.cpp
@@ -6,7 +6,6 @@
  */
 
 #include "BenchLogger.h"
-#include "BenchTimer.h"
 #include "Benchmark.h"
 #include "CrashHandler.h"
 #include "GMBench.h"
@@ -24,6 +23,7 @@
 #include "SkPictureRecorder.h"
 #include "SkString.h"
 #include "SkSurface.h"
+#include "Timer.h"
 
 #if SK_SUPPORT_GPU
 #include "GrContext.h"
@@ -530,9 +530,9 @@
             if (Benchmark::kGPU_Backend == config.backend) {
                 contextHelper = gContextFactory.getGLContext(config.contextType);
             }
-            BenchTimer timer(contextHelper);
+            Timer timer(contextHelper);
 #else
-            BenchTimer timer;
+            Timer timer;
 #endif
 
             double previous = std::numeric_limits<double>::infinity();