Bug 739972 - Stop using GetChildAt in svg layout code. r=dholbert

layout/svg/base/src/nsSVGFilterFrame.cpp

@@ -303,9 +303,9 @@ nsSVGFilterFrame::GetLengthValue(PRUint32 aIndex, nsIContent *aDefault)
 const nsSVGFilterElement *
 nsSVGFilterFrame::GetFilterContent(nsIContent *aDefault)
 {
-  PRUint32 count = mContent->GetChildCount();
-  for (PRUint32 i = 0; i < count; ++i) {
-    nsIContent* child = mContent->GetChildAt(i);
+  for (nsIContent* child = mContent->GetFirstChild();
+       child;
+       child = child->GetNextSibling()) {
     nsRefPtr<nsSVGFE> primitive;
     CallQueryInterface(child, (nsSVGFE**)getter_AddRefs(primitive));
     if (primitive) {

layout/svg/base/src/nsSVGFilterInstance.cpp

@@ -199,10 +199,9 @@ nsSVGFilterInstance::BuildPrimitives()
 {
   // First build mFilterInfo. It's important that we don't change that
   // array after we start storing pointers to its elements!
-  PRUint32 count = mFilterElement->GetChildCount();
-  PRUint32 i;
-  for (i = 0; i < count; ++i) {
-    nsIContent* child = mFilterElement->GetChildAt(i);
+  for (nsIContent* child = mFilterElement->nsINode::GetFirstChild();
+       child;
+       child = child->GetNextSibling()) {
     nsRefPtr<nsSVGFE> primitive;
     CallQueryInterface(child, (nsSVGFE**)getter_AddRefs(primitive));
     if (!primitive)
@@ -216,7 +215,7 @@ nsSVGFilterInstance::BuildPrimitives()
   nsTHashtable<ImageAnalysisEntry> imageTable;
   imageTable.Init(10);
 
-  for (i = 0; i < mPrimitives.Length(); ++i) {
+  for (PRUint32 i = 0; i < mPrimitives.Length(); ++i) {
     PrimitiveInfo* info = &mPrimitives[i];
     nsSVGFE* filter = info->mFE;
     nsAutoTArray<nsSVGStringInfo,2> sources;