Return shader variable information using GLenum values.

Instead of duplicating GL header define values, explictly return
GLenum for variable queries in the shader inspection API. This
reduces the duplicate defines in the shader compiler header.

BUG=angle:466

Change-Id: Iddaaff597b188251fa2e546f352bf77ab3ac43bc
Reviewed-on: https://chromium-review.googlesource.com/205860
Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Nicolas Capens <capn@chromium.org>
diff --git a/src/compiler/translator/ParseContext.h b/src/compiler/translator/ParseContext.h
index fc51ac8..a402eec 100644
--- a/src/compiler/translator/ParseContext.h
+++ b/src/compiler/translator/ParseContext.h
@@ -25,7 +25,7 @@
 // they can be passed to the parser without needing a global.
 //
 struct TParseContext {
-    TParseContext(TSymbolTable& symt, TExtensionBehavior& ext, TIntermediate& interm, ShShaderType type, ShShaderSpec spec, int options, bool checksPrecErrors, const char* sourcePath, TInfoSink& is) :
+    TParseContext(TSymbolTable& symt, TExtensionBehavior& ext, TIntermediate& interm, sh::GLenum type, ShShaderSpec spec, int options, bool checksPrecErrors, const char* sourcePath, TInfoSink& is) :
             intermediate(interm),
             symbolTable(symt),
             shaderType(type),
@@ -47,7 +47,7 @@
             scanner(NULL) {  }
     TIntermediate& intermediate; // to hold and build a parse tree
     TSymbolTable& symbolTable;   // symbol table that goes with the language currently being parsed
-    ShShaderType shaderType;              // vertex or fragment language (future: pack or unpack)
+    sh::GLenum shaderType;              // vertex or fragment language (future: pack or unpack)
     ShShaderSpec shaderSpec;              // The language specification compiler conforms to - GLES2 or WebGL.
     int shaderVersion;
     int compileOptions;