[oilpan] Make the oilpan branch build on Mac.

Source/WebKit/chromium/src/mac/WebSubstringUtil.mm

Index: Source/WebKit/chromium/src/mac/WebSubstringUtil.mm
diff --git a/Source/WebKit/chromium/src/mac/WebSubstringUtil.mm b/Source/WebKit/chromium/src/mac/WebSubstringUtil.mm
index 2186f0e0c97d24d3201f2f51d0a5527912d7fe7d..cd53b6e9d10f38001c1e9017d7988d56242620a9 100644
--- a/Source/WebKit/chromium/src/mac/WebSubstringUtil.mm
+++ b/Source/WebKit/chromium/src/mac/WebSubstringUtil.mm
@@ -70,12 +70,13 @@ NSAttributedString* WebSubstringUtil::attributedSubstringInRange(WebFrame* webFr
 
     unsigned position = 0;
     for (TextIterator it(range.get()); !it.atEnd() && [string length] < length; it.advance()) {
+        HandleScope scope;
         unsigned numCharacters = it.length();
         if (!numCharacters)
             continue;
 
         ExceptionCode exception = 0;
-        Node* container = it.range()->startContainer(exception);
+        Handle<Node> container = it.range()->startContainer(exception);
         RenderObject* renderer = container->renderer();
         ASSERT(renderer);
         if (!renderer)