Add detection of mip support

src/gpu/GrDrawTargetCaps.h

Index: src/gpu/GrDrawTargetCaps.h
diff --git a/src/gpu/GrDrawTargetCaps.h b/src/gpu/GrDrawTargetCaps.h
index e597e099c9430e7c56675801ef4b795ee5d846b8..b316e491c196ed4b8967099fdd2a4db2625cd51c 100644
--- a/src/gpu/GrDrawTargetCaps.h
+++ b/src/gpu/GrDrawTargetCaps.h
@@ -28,6 +28,9 @@ public:
 
     bool eightBitPaletteSupport() const { return f8BitPaletteSupport; }
     bool npotTextureTileSupport() const { return fNPOTTextureTileSupport; }
+    /** To avoid as-yet-unnecessary complexity we don't allow any partial support of MIP Maps (e.g.
+        only for POT textures) */
+    bool mipMapSupport() const { return fMipMapSupport; }
     bool twoSidedStencilSupport() const { return fTwoSidedStencilSupport; }
     bool stencilWrapOpsSupport() const { return  fStencilWrapOpsSupport; }
     bool hwAALineSupport() const { return fHWAALineSupport; }
@@ -57,6 +60,7 @@ public:
 protected:
     bool f8BitPaletteSupport        : 1;
     bool fNPOTTextureTileSupport    : 1;
+    bool fMipMapSupport             : 1;
     bool fTwoSidedStencilSupport    : 1;
     bool fStencilWrapOpsSupport     : 1;
     bool fHWAALineSupport           : 1;