demo tweaks, scale up perlin, add call to flush for fps

BUG=skia:
TBR=bsalomon

Review URL: https://codereview.chromium.org/1419983006
diff --git a/samplecode/SampleApp.cpp b/samplecode/SampleApp.cpp
index df83d4d..c71fda5 100644
--- a/samplecode/SampleApp.cpp
+++ b/samplecode/SampleApp.cpp
@@ -1441,6 +1441,7 @@
 
     // Do this after presentGL and other finishing, rather than in afterChild
     if (fMeasureFPS) {
+        orig->flush();
         fTimer.end();
         fMeasureFPS_Time += fTimer.fWall;
     }