Don't allow renderTarget==NULL to GrContext::clear() and friends.

src/effects/SkGpuBlurUtils.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkGpuBlurUtils.h"
 
 #include "SkRect.h"
@@ skipping 232 matching lines @@
         srcRect = dstRect;
         SkTSwap(dstTexture, tempTexture);
 
     } else {
         if (sigmaX > 0.0f) {
             if (scaleFactorX > 1) {
                 // Clear out a radius to the right of the srcRect to prevent the
                 // X convolution from reading garbage.
                 clearRect = SkIRect::MakeXYWH(srcIRect.fRight, srcIRect.fTop,
                                               radiusX, srcIRect.height());
-                context->clear(&clearRect, 0x0, false);
+                context->clear(&clearRect, 0x0, false, context->getRenderTarget());
             }
             context->setRenderTarget(dstTexture->asRenderTarget());
             SkRect dstRect = SkRect::MakeWH(srcRect.width(), srcRect.height());
             convolve_gaussian(context, srcRect, dstRect, srcTexture,
                               Gr1DKernelEffect::kX_Direction, radiusX, sigmaX, cropToRect);
             srcTexture = dstTexture;
             srcRect = dstRect;
             SkTSwap(dstTexture, tempTexture);
         }
 
         if (sigmaY > 0.0f) {
             if (scaleFactorY > 1 || sigmaX > 0.0f) {
                 // Clear out a radius below the srcRect to prevent the Y
                 // convolution from reading garbage.
                 clearRect = SkIRect::MakeXYWH(srcIRect.fLeft, srcIRect.fBottom,
                                               srcIRect.width(), radiusY);
-                context->clear(&clearRect, 0x0, false);
+                context->clear(&clearRect, 0x0, false, context->getRenderTarget());
             }
 
             context->setRenderTarget(dstTexture->asRenderTarget());
             SkRect dstRect = SkRect::MakeWH(srcRect.width(), srcRect.height());
             convolve_gaussian(context, srcRect, dstRect, srcTexture,
                               Gr1DKernelEffect::kY_Direction, radiusY, sigmaY, cropToRect);
             srcTexture = dstTexture;
             srcRect = dstRect;
             SkTSwap(dstTexture, tempTexture);
         }
     }
 
     if (scaleFactorX > 1 || scaleFactorY > 1) {
         // Clear one pixel to the right and below, to accommodate bilinear
         // upsampling.
         clearRect = SkIRect::MakeXYWH(srcIRect.fLeft, srcIRect.fBottom,
                                       srcIRect.width() + 1, 1);
-        context->clear(&clearRect, 0x0, false);
+        context->clear(&clearRect, 0x0, false, context->getRenderTarget());
         clearRect = SkIRect::MakeXYWH(srcIRect.fRight, srcIRect.fTop,
                                       1, srcIRect.height());
-        context->clear(&clearRect, 0x0, false);
+        context->clear(&clearRect, 0x0, false, context->getRenderTarget());
         SkMatrix matrix;
         matrix.setIDiv(srcTexture->width(), srcTexture->height());
         context->setRenderTarget(dstTexture->asRenderTarget());
 
         GrPaint paint;
         // FIXME:  this should be mitchell, not bilinear.
         GrTextureParams params(SkShader::kClamp_TileMode, GrTextureParams::kBilerp_FilterMode);
         paint.addColorTextureProcessor(srcTexture, matrix, params);
 
         SkRect dstRect(srcRect);
         scale_rect(&dstRect, (float) scaleFactorX, (float) scaleFactorY);
         context->drawRectToRect(paint, dstRect, srcRect);
         srcRect = dstRect;
         srcTexture = dstTexture;
         SkTSwap(dstTexture, tempTexture);
     }
     return SkRef(srcTexture);
 }
 #endif
 
 }