Remove const from `const int loops`.

This drives me nuts, and prevents `while (loops --> 0)`.

BUG=skia:

Review URL: https://codereview.chromium.org/1379923005
diff --git a/bench/GrResourceCacheBench.cpp b/bench/GrResourceCacheBench.cpp
index d022f19..bc38035 100644
--- a/bench/GrResourceCacheBench.cpp
+++ b/bench/GrResourceCacheBench.cpp
@@ -69,7 +69,7 @@
         return fFullName.c_str();
     }
 
-    void onDraw(const int loops, SkCanvas* canvas) override {
+    void onDraw(int loops, SkCanvas* canvas) override {
         SkAutoTUnref<GrContext> context(GrContext::CreateMockContext());
         if (nullptr == context) {
             return;
@@ -134,7 +134,7 @@
         populate_cache(gpu, CACHE_SIZE_COUNT, fKeyData32Count);
     }
 
-    void onDraw(const int loops, SkCanvas* canvas) override {
+    void onDraw(int loops, SkCanvas* canvas) override {
         if (!fContext) {
             return;
         }