fix numerical overflows in 565 blends

bench/nanobench.cpp

Index: bench/nanobench.cpp
diff --git a/bench/nanobench.cpp b/bench/nanobench.cpp
index 6968d6dac21deb835f11063a4731b3077673398e..ac49e843807e93efd8986b0b2ffe50b599201279 100644
--- a/bench/nanobench.cpp
+++ b/bench/nanobench.cpp
@@ -595,14 +595,6 @@ int nanobench_main() {
             SkCanvas* canvas = targets[j]->surface.get() ? targets[j]->surface->getCanvas() : NULL;
             const char* config = targets[j]->config.name;
 
-#ifdef SK_DEBUG
-            // skia:2797  Some SKPs SkASSERT in debug mode.  Skip them for now.
-            if (0 == strcmp("565", config) && SkStrContains(bench->getName(), ".skp")) {
-                SkDebugf("Skipping 565 %s.  See skia:2797\n", bench->getName());
-                continue;
-            }
-#endif
-
             const int loops =
 #if SK_SUPPORT_GPU
                 Benchmark::kGPU_Backend == targets[j]->config.backend