Fix garbage showing up beneath dialogs

bug:17463894

Fixes the setViewport method to immediately affect the return values
of getViewportWidth/Height methods.

Also works around tiling extension issues observed on first frame
after window resize by disabling tiling for that frame.

Change-Id: Ie172d572d20d74a1be9cc58ad389af2cffa0e4b6
diff --git a/libs/hwui/OpenGLRenderer.h b/libs/hwui/OpenGLRenderer.h
index e295b1a..47ef1a9 100755
--- a/libs/hwui/OpenGLRenderer.h
+++ b/libs/hwui/OpenGLRenderer.h
@@ -1013,6 +1013,7 @@
 
     // No-ops start/endTiling when set
     bool mSuppressTiling;
+    bool mFirstFrameAfterResize;
 
     // If true, this renderer will setup drawing to emulate
     // an increment stencil buffer in the color buffer