Bug 1113010 (part 0) - Remove impossible path in AddFrameConstruct(). r=dholbert.

Infallible new ensures that |item| is always non-null. And even if it didn't,
AppendItem() dereferences |item| before this code is reached.

--HG--
extra : rebase_source : 9abb8704ba03f455d6b77c5735fcb6cde4f8fef8

layout/base/nsCSSFrameConstructor.cpp

@@ -5691,13 +5691,6 @@ nsCSSFrameConstructor::AddFrameConstructionItemsInternal(nsFrameConstructorState
     aItems.AppendItem(data, aContent, aTag, aNameSpaceID,
                       pendingBinding, styleContext.forget(),
                       aSuppressWhiteSpaceOptimizations, aAnonChildren);
-  if (!item) {
-    if (isGeneratedContent) {
-      aContent->UnbindFromTree();
-    }
-    return;
-  }
-
   item->mIsText = isText;
   item->mIsGeneratedContent = isGeneratedContent;
   item->mIsAnonymousContentCreatorContent =

layout/base/nsCSSFrameConstructor.h

@@ -831,6 +831,7 @@ private:
     // aSuppressWhiteSpaceOptimizations is true if optimizations that
     // skip constructing whitespace frames for this item or items
     // around it cannot be performed.
+    // Also, the return value is always non-null, thanks to infallible 'new'.
     FrameConstructionItem* AppendItem(const FrameConstructionData* aFCData,
                                       nsIContent* aContent,
                                       nsIAtom* aTag,