Add new Query class for debugging

This class can be used to perform occlusion queries. An occlusion query
can be used to test whether an object is entirely hidden or not.

Change-Id: Ida456df81dbe008a64d3ff4cb7879340785c6abf
diff --git a/libs/hwui/Dither.cpp b/libs/hwui/Dither.cpp
index 649a7bc..77006a4 100644
--- a/libs/hwui/Dither.cpp
+++ b/libs/hwui/Dither.cpp
@@ -29,7 +29,7 @@
 
 void Dither::bindDitherTexture() {
     if (!mInitialized) {
-        bool useFloatTexture = Extensions::getInstance().getMajorGlVersion() >= 3;
+        bool useFloatTexture = Extensions::getInstance().hasFloatTextures();
 
         glGenTextures(1, &mDitherTexture);
         mCaches->bindTexture(mDitherTexture);