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/BenchLogger.cpp b/bench/BenchLogger.cpp
new file mode 100644
index 0000000..98423d0
--- /dev/null
+++ b/bench/BenchLogger.cpp
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "BenchLogger.h"
+
+#include "SkStream.h"
+
+BenchLogger::BenchLogger()
+: fFileStream(NULL) {}
+
+BenchLogger::~BenchLogger() {
+    if (fFileStream) {
+        SkDELETE(fFileStream);
+    }
+}
+
+bool BenchLogger::SetLogFile(const char *file) {
+    fFileStream = SkNEW_ARGS(SkFILEWStream, (file));
+    return fFileStream->isValid();
+}
+
+void BenchLogger::fileWrite(const char msg[], size_t size) {
+    if (fFileStream && fFileStream->isValid()) {
+        fFileStream->write(msg, size);
+    }
+}