Fix texture allocation in SWMaskHelper

src/gpu/GrSWMaskHelper.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrSWMaskHelper.h"
 #include "GrDrawState.h"
 #include "GrGpu.h"
@@ skipping 112 matching lines @@
     desc.fHeight = fBM.height();
     desc.fConfig = kAlpha_8_GrPixelConfig;
 
     texture->set(fContext, desc);
     return NULL != texture->texture();
 }
 
 /**
  * Move the result of the software mask generation back to the gpu
  */
-void GrSWMaskHelper::toTexture(GrTexture *texture, uint8_t alpha) {
+void GrSWMaskHelper::toTexture(GrTexture *texture) {
     SkAutoLockPixels alp(fBM);
 
-    // The destination texture is almost always larger than "fBM". Clear
-    // it appropriately so we don't get mask artifacts outside of the path's
-    // bounding box
-
-    // "texture" needs to be installed as the render target for the clear
-    // and the texture upload but cannot remain the render target upon
-    // return. Callers typically use it as a texture and it would then
-    // be both source and dest.
-    GrDrawState::AutoRenderTargetRestore artr(fContext->getGpu()->drawState(),
-                                              texture->asRenderTarget());
-
-    fContext->getGpu()->clear(NULL, GrColorPackRGBA(alpha, alpha, alpha, alpha));
-
     texture->writePixels(0, 0, fBM.width(), fBM.height(),
                          kAlpha_8_GrPixelConfig,
                          fBM.getPixels(), fBM.rowBytes());
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 /**
  * Software rasterizes path to A8 mask (possibly using the context's matrix)
  * and uploads the result to a scratch texture. Returns the resulting
  * texture on success; NULL on failure.
@@ skipping 11 matching lines @@
     if (!helper.init(resultBounds, matrix)) {
         return NULL;
     }
 
     helper.draw(path, stroke, SkRegion::kReplace_Op, antiAlias, 0xFF);
 
     if (!helper.getTexture(&ast)) {
         return NULL;
     }
 
-    helper.toTexture(ast.texture(), 0x00);
+    helper.toTexture(ast.texture());
 
     return ast.detach();
 }
 
 void GrSWMaskHelper::DrawToTargetWithPathMask(GrTexture* texture,
                                               GrDrawTarget* target,
                                               const SkIRect& rect) {
     GrDrawState* drawState = target->drawState();
 
     GrDrawState::AutoViewMatrixRestore avmr;
@@ skipping 17 matching lines @@
     maskMatrix.preConcat(drawState->getViewMatrix());
 
     drawState->addCoverageEffect(
                          GrSimpleTextureEffect::Create(texture,
                                                        maskMatrix,
                                                        false,
                                                        GrEffect::kPosition_CoordsType))->unref();
 
     target->drawSimpleRect(dstRect);
 }