Make GrPaint have a variable sized array of color and coverage stages rather than a fixed size.

src/effects/SkBlendImageFilter.cpp

 /*
  * Copyright 2012 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBlendImageFilter.h"
 #include "SkCanvas.h"
 #include "SkColorPriv.h"
@@ skipping 176 matching lines @@
     desc.fWidth = src.width();
     desc.fHeight = src.height();
     desc.fConfig = kSkia8888_GrPixelConfig;
 
     GrAutoScratchTexture ast(context, desc);
     SkAutoTUnref<GrTexture> dst(ast.detach());
 
     GrContext::AutoRenderTarget art(context, dst->asRenderTarget());
 
     GrPaint paint;
-    paint.colorStage(0)->setEffect(
-        GrBlendEffect::Create(fMode, foreground, foregroundOffset, background, backgroundOffset))->unref();
+    paint.addColorEffect(GrBlendEffect::Create(fMode,
+                                               foreground, foregroundOffset,
+                                               background, backgroundOffset))->unref();
     SkRect srcRect;
     src.getBounds(&srcRect);
     context->drawRect(paint, srcRect);
     return SkImageFilterUtils::WrapTexture(dst, src.width(), src.height(), result);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 GrBlendEffect::GrBlendEffect(SkBlendImageFilter::Mode mode,
                              GrTexture* foreground,
@@ skipping 130 matching lines @@
     EffectKey bgKey = GrGLEffectMatrix::GenKey(GrEffect::MakeDivByTextureWHMatrix(bgTex),
                                                drawEffect,
                                                kCoordsType,
                                                bgTex);
     bgKey <<= GrGLEffectMatrix::kKeyBits;
     EffectKey modeKey = blend.mode() << (2 * GrGLEffectMatrix::kKeyBits);
 
     return  modeKey | bgKey | fgKey;
 }
 #endif