skia: Holding onto the image in the benchmark causes issues

bench/ImageBench.cpp

Index: bench/ImageBench.cpp
diff --git a/bench/ImageBench.cpp b/bench/ImageBench.cpp
index 89fbcd6aeff48565cd9b163c4bcb13e43296e5d2..56649fbc2c92d84bb97f04309d9b4d28660aa707 100644
--- a/bench/ImageBench.cpp
+++ b/bench/ImageBench.cpp
@@ -39,6 +39,11 @@ protected:
         fRasterSurface.reset(SkSurface::NewRaster(info));
     }
 
+    void onPerCanvasPostDraw(SkCanvas*) override {
+        fRasterSurface.reset(nullptr);

[mtklein, 2015/11/23 22:13:04]

let's add a note about why we do this proactively?

+        fImage.reset(nullptr);
+    }
+
     void onDraw(int loops, SkCanvas*) override {
         for (int i = 0; i < loops; i++) {
             for (int inner = 0; inner < 10; ++inner) {