Trying to be consistent when members are allowed to be NULL

src/effects/SkRectShaderImageFilter.cpp

Index: src/effects/SkRectShaderImageFilter.cpp
diff --git a/src/effects/SkRectShaderImageFilter.cpp b/src/effects/SkRectShaderImageFilter.cpp
index fb34ed0007152f124ae557a5567aad4effa3bed5..0a2930e999ae11101cfead4d92a3e9443fb1e522 100644
--- a/src/effects/SkRectShaderImageFilter.cpp
+++ b/src/effects/SkRectShaderImageFilter.cpp
@@ -20,12 +20,12 @@ SkRectShaderImageFilter* SkRectShaderImageFilter::Create(SkShader* s, const SkRe
         flags = 0x0;
     }
     CropRect cropRect(rect, flags);
-    return SkNEW_ARGS(SkRectShaderImageFilter, (s, &cropRect));
+    return s ? SkNEW_ARGS(SkRectShaderImageFilter, (s, &cropRect)) : NULL;
 }
 
 SkRectShaderImageFilter* SkRectShaderImageFilter::Create(SkShader* s, const CropRect* cropRect, uint32_t uniqueID) {
     SkASSERT(s);
-    return SkNEW_ARGS(SkRectShaderImageFilter, (s, cropRect, uniqueID));
+    return s ? SkNEW_ARGS(SkRectShaderImageFilter, (s, cropRect, uniqueID)) : NULL;
 }
 
 SkRectShaderImageFilter::SkRectShaderImageFilter(SkShader* s, const CropRect* cropRect,
@@ -33,7 +33,7 @@ SkRectShaderImageFilter::SkRectShaderImageFilter(SkShader* s, const CropRect* cr
   : INHERITED(0, NULL, cropRect, uniqueID)
   , fShader(s) {
     SkASSERT(s);
-    s->ref();
+    SkSafeRef(s);

[reed1, 2014/10/29 18:27:08]

When can this be NULL?

[sugoi1, 2014/10/29 18:30:58]

I was just trying to have the constructor and destructor to be consistent with
each other, I'll change the destructor instead.

 }
 
 #ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
@@ -78,7 +78,7 @@ bool SkRectShaderImageFilter::onFilterImage(Proxy* proxy,
     SkPaint paint;
     SkMatrix matrix(ctx.ctm());
     matrix.postTranslate(SkIntToScalar(-bounds.left()), SkIntToScalar(-bounds.top()));
-    paint.setShader(SkShader::CreateLocalMatrixShader(fShader, matrix))->unref();
+    SkSafeUnref(paint.setShader(SkShader::CreateLocalMatrixShader(fShader, matrix)));
 
     SkRect rect = SkRect::MakeWH(SkIntToScalar(bounds.width()), SkIntToScalar(bounds.height()));
     canvas.drawRect(rect, paint);