Simplify benchmark internal API.

I'm not quite sure why I wrote such a convoluted API with setLoops()/getLoops().
This replaces it with a loops argument passed to onDraw().

This CL is largely mechanical translation from the old API to the new one.
MathBench used this->getLoops() outside onDraw(), which seems incorrect.  I
fixed it.

BUG=
R=djsollen@google.com

Author: mtklein@google.com

Review URL: https://codereview.chromium.org/99893003

git-svn-id: http://skia.googlecode.com/svn/trunk@12466 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/bench/PremulAndUnpremulAlphaOpsBench.cpp b/bench/PremulAndUnpremulAlphaOpsBench.cpp
index aac5934..93c84c9 100644
--- a/bench/PremulAndUnpremulAlphaOpsBench.cpp
+++ b/bench/PremulAndUnpremulAlphaOpsBench.cpp
@@ -25,7 +25,7 @@
         return fName.c_str();
     }
 
-    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+    virtual void onDraw(const int loops, SkCanvas* canvas) SK_OVERRIDE {
         canvas->clear(SK_ColorBLACK);
         SkISize size = canvas->getDeviceSize();
 
@@ -45,7 +45,7 @@
         bmp2.setConfig(SkBitmap::kARGB_8888_Config, size.width(),
                        size.height());
 
-        for (int loop = 0; loop < this->getLoops(); ++loop) {
+        for (int loop = 0; loop < loops; ++loop) {
             // Unpremul -> Premul
             canvas->writePixels(bmp1, 0, 0, fUnPremulConfig);
             // Premul -> Unpremul