Revert of Add infastructure for gl_SampleMask

src/gpu/glsl/GrGLSLCaps.cpp

Index: src/gpu/glsl/GrGLSLCaps.cpp
diff --git a/src/gpu/glsl/GrGLSLCaps.cpp b/src/gpu/glsl/GrGLSLCaps.cpp
index 7116f5deb02143c6c4c528f8305e26934b26dfb8..ba99be57e26ddb44b30a3728ee5ef1dda417c6ca 100755
--- a/src/gpu/glsl/GrGLSLCaps.cpp
+++ b/src/gpu/glsl/GrGLSLCaps.cpp
@@ -23,13 +23,10 @@
     fCanUseAnyFunctionInShader = true;
     fCanUseMinAndAbsTogether = true;
     fMustForceNegatedAtanParamToFloat = false;
-    fSampleVariablesSupport = false;
-    fSampleMaskOverrideCoverageSupport = false;
     fFlatInterpolationSupport = false;
     fNoPerspectiveInterpolationSupport = false;
     fVersionDeclString = nullptr;
     fShaderDerivativeExtensionString = nullptr;
-    fSampleVariablesExtensionString = nullptr;
     fFragCoordConventionsExtensionString = nullptr;
     fSecondaryOutputExtensionString = nullptr;
     fExternalTextureExtensionString = nullptr;
@@ -64,9 +61,6 @@
     r.appendf("Can use min() and abs() together: %s\n", (fCanUseMinAndAbsTogether ? "YES" : "NO"));
     r.appendf("Must force negated atan param to float: %s\n", (fMustForceNegatedAtanParamToFloat ?
                                                                "YES" : "NO"));
-    r.appendf("Sample variables support: %s\n", (fSampleVariablesSupport ? "YES" : "NO"));
-    r.appendf("Sample mask override coverage support: %s\n", (fSampleMaskOverrideCoverageSupport ?
-                                                              "YES" : "NO"));
     r.appendf("Flat interpolation support: %s\n", (fFlatInterpolationSupport ?  "YES" : "NO"));
     r.appendf("No perspective interpolation support: %s\n", (fNoPerspectiveInterpolationSupport ?
                                                              "YES" : "NO"));