Benchmark-mode for macrobench

Adds googlebench output format support
Adds offscreen rendering for >60fps benchmarking
Adds 'all' alias to run all registered TestScenes

Change-Id: I2579e40f2f4c941bfbd90c75efbee384c08a116b
diff --git a/libs/hwui/tests/common/TestScene.h b/libs/hwui/tests/common/TestScene.h
index 706f2ff..d4a6646 100644
--- a/libs/hwui/tests/common/TestScene.h
+++ b/libs/hwui/tests/common/TestScene.h
@@ -38,6 +38,7 @@
     struct Options {
         int count = 0;
         int reportFrametimeWeight = 0;
+        bool renderOffscreen = false;
     };
 
     template <class T>