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/Properties.h b/libs/hwui/Properties.h
index 8fec429..cdfc081 100644
--- a/libs/hwui/Properties.h
+++ b/libs/hwui/Properties.h
@@ -295,6 +295,7 @@
 
     // Should be used only by test apps
     static bool waitForGpuCompletion;
+    static bool forceDrawFrame;
 
     // Should only be set by automated tests to try and filter out
     // any overhead they add