Remove gl::Varying::elementIndex.

We only assigned to elementIndex, and never referenced the value
at any point in our code.

BUG=angle:466

Change-Id: I541a353110bcd1863b07b21bcf21fad38be19ca1
Reviewed-on: https://chromium-review.googlesource.com/199735
Reviewed-by: Nicolas Capens <nicolascapens@chromium.org>
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>

src/common/shadervars.h

@@ -106,14 +106,12 @@ struct Varying : public ShaderVariable
     InterpolationType interpolation;
     std::vector<Varying> fields;
     unsigned int registerIndex;    // Assigned during link
-    unsigned int elementIndex;     // First register element for varyings, assigned during link
     std::string structName;
 
     Varying(GLenum typeIn, GLenum precisionIn, const char *nameIn, unsigned int arraySizeIn, InterpolationType interpolationIn)
       : ShaderVariable(typeIn, precisionIn, nameIn, arraySizeIn),
         interpolation(interpolationIn),
-        registerIndex(GL_INVALID_INDEX),
-        elementIndex(GL_INVALID_INDEX)
+        registerIndex(GL_INVALID_INDEX)
     {}
 
     bool isStruct() const { return !fields.empty(); }
@@ -122,7 +120,6 @@ struct Varying : public ShaderVariable
     void resetRegisterAssignment()
     {
         registerIndex = GL_INVALID_INDEX;
-        elementIndex = GL_INVALID_INDEX;
     }
 };
 

src/libGLESv2/DynamicHLSL.cpp

@@ -118,7 +118,6 @@ static bool packVarying(Varying *varying, const int maxVaryingVectors, const Sha
             if (available)
             {
                 varying->registerIndex = r;
-                varying->elementIndex = 0;
 
                 for (int y = 0; y < registers; y++)
                 {
@@ -152,7 +151,6 @@ static bool packVarying(Varying *varying, const int maxVaryingVectors, const Sha
                 if (available)
                 {
                     varying->registerIndex = r;
-                    varying->elementIndex = 2;
 
                     for (int y = 0; y < registers; y++)
                     {
@@ -206,8 +204,6 @@ static bool packVarying(Varying *varying, const int maxVaryingVectors, const Sha
                 }
             }
 
-            varying->elementIndex = column;
-
             success = true;
         }
     }

src/libGLESv2/ProgramBinary.cpp

@@ -1032,7 +1032,6 @@ bool ProgramBinary::linkVaryings(InfoLog &infoLog, FragmentShader *fragmentShade
                 }
 
                 output->registerIndex = input->registerIndex;
-                output->elementIndex = input->elementIndex;
 
                 matched = true;
                 break;