release the scanline textures in GrRectBlurEffect

src/effects/SkBlurMaskFilter.cpp

Index: src/effects/SkBlurMaskFilter.cpp
diff --git a/src/effects/SkBlurMaskFilter.cpp b/src/effects/SkBlurMaskFilter.cpp
index 5cb98153f0231b539f142c050e820e9d0d1fb0b6..9b3354484b9a02ce5151f65f1557744a7dd84002 100644
--- a/src/effects/SkBlurMaskFilter.cpp
+++ b/src/effects/SkBlurMaskFilter.cpp
@@ -527,17 +527,18 @@ public:
      */
     static GrEffectRef* Create(GrContext *context, const SkRect& rect,
                                float sigma) {
-        GrTexture *horizontalScanline, *verticalScanline;
+        GrTexture *horizontalScanline = NULL, *verticalScanline = NULL;
         bool createdScanlines = CreateScanlineTextures(context, sigma,
                                                        SkScalarCeilToInt(rect.width()),
                                                        SkScalarCeilToInt(rect.height()),
                                                        &horizontalScanline, &verticalScanline);

[robertphillips, 2014/01/31 13:33:10]

Won't this potentially cause a problem if the horizontal texture gets created
(and unrefed in CreateScanlineTextures) but the vertical texture doesn't get
created. Don't we also need to set horizontalScanline to NULL in that case (in
CreateScanlineTextures)?

[humper, 2014/01/31 13:51:17]

yeah, I'll land a better fix for this once this patch arrives.

-        if (!createdScanlines) {
+         SkAutoTUnref<GrTexture> hunref(horizontalScanline), vunref(verticalScanline);
+         if (!createdScanlines) {
             return NULL;
         }
         AutoEffectUnref effect(SkNEW_ARGS(GrRectBlurEffect, (rect, sigma,
                                                              horizontalScanline, verticalScanline)));
-        return CreateEffectRef(effect);
+        return CreateEffectRef(effect);    
     }
 
     unsigned int getWidth() const { return fWidth; }
@@ -686,6 +687,7 @@ bool GrRectBlurEffect::CreateScanlineTextures(GrContext *context, float sigma,
                                                    verticalPixels, 0);
 
         if (NULL == *verticalScanline) {
+            (*horizontalScanline)->unref();
             return false;
         }