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/libGLESv2/Shader.cpp b/src/libGLESv2/Shader.cpp
index 5b0f3ff..013922b1 100644
--- a/src/libGLESv2/Shader.cpp
+++ b/src/libGLESv2/Shader.cpp
@@ -206,8 +206,8 @@
             resources.MinProgramTexelOffset = -8;   // D3D10_COMMONSHADER_TEXEL_OFFSET_MAX_NEGATIVE
             resources.MaxProgramTexelOffset = 7;    // D3D10_COMMONSHADER_TEXEL_OFFSET_MAX_POSITIVE
 
-            mFragmentCompiler = ShConstructCompiler(SH_FRAGMENT_SHADER, SH_GLES2_SPEC, hlslVersion, &resources);
-            mVertexCompiler = ShConstructCompiler(SH_VERTEX_SHADER, SH_GLES2_SPEC, hlslVersion, &resources);
+            mFragmentCompiler = ShConstructCompiler(GL_FRAGMENT_SHADER, SH_GLES2_SPEC, hlslVersion, &resources);
+            mVertexCompiler = ShConstructCompiler(GL_VERTEX_SHADER, SH_GLES2_SPEC, hlslVersion, &resources);
         }
     }
 }