Add compressed texture capabilities for GPU devices

src/gpu/GrDrawTargetCaps.h

Index: src/gpu/GrDrawTargetCaps.h
diff --git a/src/gpu/GrDrawTargetCaps.h b/src/gpu/GrDrawTargetCaps.h
index 648b5c36be15a523b96e47fc7c18d487715fb0c8..681327cdc7c2ec08dae3f22eb524151fc0c5b2ca 100644
--- a/src/gpu/GrDrawTargetCaps.h
+++ b/src/gpu/GrDrawTargetCaps.h
@@ -72,6 +72,11 @@ public:
         return fConfigRenderSupport[config][withMSAA];
     }
 
+    bool compressedTextureSupport(GrCompressedFormat format) const {
+        SkASSERT(format < kCompressedFormatCount);
+        return fCompressedFormatSupport[format];
+    }
+
 protected:
     bool f8BitPaletteSupport        : 1;
     bool fNPOTTextureTileSupport    : 1;
@@ -97,6 +102,8 @@ protected:
     // The first entry for each config is without msaa and the second is with.
     bool fConfigRenderSupport[kGrPixelConfigCnt][2];
 
+    bool fCompressedFormatSupport[kCompressedFormatCount];
+
     typedef SkRefCnt INHERITED;
 };