added support for glMinSampleShading

include/gpu/GrCaps.h

Index: include/gpu/GrCaps.h
diff --git a/include/gpu/GrCaps.h b/include/gpu/GrCaps.h
index 398517cb6858843b6c829331e7c4f1e62c8a33b0..9c62adfaf97c39455e09876bd58a8cdff31b7841 100644
--- a/include/gpu/GrCaps.h
+++ b/include/gpu/GrCaps.h
@@ -269,6 +269,8 @@ public:
         is not initialized (even if not read by draw calls). */
     bool mustClearUploadedBufferData() const { return fMustClearUploadedBufferData; }
 
+    bool sampleShadingSupport() const { return fSampleShadingSupport; }
+
 protected:
     /** Subclasses must call this at the end of their constructors in order to apply caps
         overrides requested by the client. Note that overrides will only reduce the caps never
@@ -303,6 +305,8 @@ protected:
     // ANGLE workaround
     bool fPreferVRAMUseOverFlushes                   : 1;
 
+    bool fSampleShadingSupport                       : 1;
+
     BlendEquationSupport fBlendEquationSupport;
     uint32_t fAdvBlendEqBlacklist;
     GR_STATIC_ASSERT(kLast_GrBlendEquation < 32);