Enable init'ed but unused var warning on windows for closer parity with mac/linux warnings.

src/device/xps/SkXPSDevice.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef UNICODE
 #define UNICODE
 #endif
@@ skipping 932 matching lines @@
     info.fColorOffsets = NULL;
     SkShader::GradientType gradientType = shader->asAGradient(&info);
 
     if (SkShader::kNone_GradientType == gradientType) {
         //Nothing to see, move along.
 
     } else if (SkShader::kColor_GradientType == gradientType) {
         SkASSERT(1 == info.fColorCount);
         SkColor color;
         info.fColors = &color;
-        SkShader::GradientType gradientType = shader->asAGradient(&info);
+        shader->asAGradient(&info);
         SkAlpha alpha = skPaint.getAlpha();
         HR(this->createXpsSolidColorBrush(color, alpha, brush));
         return S_OK;
 
     } else {
         if (info.fColorCount == 0) {
             const SkColor color = skPaint.getColor();
             HR(this->createXpsSolidColorBrush(color, 0xFF, brush));
             return S_OK;
         }
@@ skipping 1446 matching lines @@
              IID_PPV_ARGS(&this->fXpsFactory)),
          "Could not create factory for layer.");
 
     HRVM(this->fXpsFactory->CreateCanvas(&this->fCurrentXpsCanvas),
          "Could not create canvas for layer.");
 }
 
 bool SkXPSDevice::allowImageFilter(SkImageFilter*) {
     return false;
 }