Remove CSS Shader related code

CSS shader has been removed from spec and chrome code base. Remove the
code in ANGLE.

BUG=chromium:233383

Change-Id: I93a35437f540e51ce7af9d49f21ca60d7c0b156a
Reviewed-on: https://chromium-review.googlesource.com/378739
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/compiler/translator/Compiler.h b/src/compiler/translator/Compiler.h
index 6b68237..600ff72 100644
--- a/src/compiler/translator/Compiler.h
+++ b/src/compiler/translator/Compiler.h
@@ -31,8 +31,7 @@
 #endif // ANGLE_ENABLE_HLSL
 
 //
-// Helper function to identify specs that are based on the WebGL spec,
-// like the CSS Shaders spec.
+// Helper function to identify specs that are based on the WebGL spec.
 //
 bool IsWebGLBasedSpec(ShShaderSpec spec);
 
@@ -119,8 +118,6 @@
     bool checkCallDepth();
     // Returns true if a program has no conflicting or missing fragment outputs
     bool validateOutputs(TIntermNode* root);
-    // Rewrites a shader's intermediate tree according to the CSS Shaders spec.
-    void rewriteCSSShader(TIntermNode* root);
     // Returns true if the given shader does not exceed the minimum
     // functionality mandated in GLSL 1.0 spec Appendix A.
     bool validateLimitations(TIntermNode* root);