Remove Sk prefix from some bench classes.

This idea came while commenting on
https://codereview.chromium.org/343583005/

Since SkBenchmark, SkBenchLogger and SkGMBench are not part of the Skia library,
they should not have the Sk prefix.

BUG=None
TEST=make all
R=mtklein@google.com

Author: tfarina@chromium.org

Review URL: https://codereview.chromium.org/347823004
diff --git a/bench/GrOrderedSetBench.cpp b/bench/GrOrderedSetBench.cpp
index 4d32f0d..dde1c4a 100644
--- a/bench/GrOrderedSetBench.cpp
+++ b/bench/GrOrderedSetBench.cpp
@@ -5,7 +5,7 @@
  * found in the LICENSE file.
  */
 
-#include "SkBenchmark.h"
+#include "Benchmark.h"
 #include "SkCanvas.h"
 #include "SkRandom.h"
 #include "SkString.h"
@@ -15,7 +15,7 @@
 static const int NUM_ELEMENTS = 1000;
 
 // Time how long it takes to build a set
-class GrOrderedSetBuildBench : public SkBenchmark {
+class GrOrderedSetBuildBench : public Benchmark {
 public:
     GrOrderedSetBuildBench() {
         fName.append("ordered_set_build");
@@ -52,11 +52,11 @@
 private:
     SkString fName;
     int fData[NUM_ELEMENTS];
-    typedef SkBenchmark INHERITED;
+    typedef Benchmark INHERITED;
 };
 
 // Time how long it takes to find elements in a set
-class GrOrderedSetFindBench : public SkBenchmark {
+class GrOrderedSetFindBench : public Benchmark {
 public:
     GrOrderedSetFindBench() {
         fName.append("ordered_set_find");
@@ -93,11 +93,11 @@
     SkString fName;
     int fData[NUM_ELEMENTS];
     GrOrderedSet<int> fSet;
-    typedef SkBenchmark INHERITED;
+    typedef Benchmark INHERITED;
 };
 
 // Time how long it takes to iterate over and remove all elements from set
-class GrOrderedSetRemoveBench : public SkBenchmark {
+class GrOrderedSetRemoveBench : public Benchmark {
 public:
     GrOrderedSetRemoveBench() {
         fName.append("ordered_set_remove");
@@ -137,7 +137,7 @@
 private:
     SkString fName;
     GrOrderedSet<int> fSet;
-    typedef SkBenchmark INHERITED;
+    typedef Benchmark INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////