Major bench refactoring.
   - Use FLAGS_.
   - Remove outer repeat loop.
   - Tune inner loop automatically.

BUG=skia:1590
R=epoger@google.com, scroggo@google.com

Review URL: https://codereview.chromium.org/23478013

git-svn-id: http://skia.googlecode.com/svn/trunk@11187 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/bench/ImageDecodeBench.cpp b/bench/ImageDecodeBench.cpp
index 1cb29b1..2e50ec5 100644
--- a/bench/ImageDecodeBench.cpp
+++ b/bench/ImageDecodeBench.cpp
@@ -59,7 +59,7 @@
 #endif
         // Decode a bunch of times
         SkBitmap bm;
-        for (int i = 0; i < SkBENCHLOOP(1000); ++i) {
+        for (int i = 0; i < this->getLoops(); ++i) {
             SkDEBUGCODE(bool success =) SkImageDecoder::DecodeStream(&fStream, &bm);
 #ifdef SK_DEBUG
             if (!success) {