Have Frame::tree() return a reference

Source/core/inspector/InspectorPageAgent.cpp

Index: Source/core/inspector/InspectorPageAgent.cpp
diff --git a/Source/core/inspector/InspectorPageAgent.cpp b/Source/core/inspector/InspectorPageAgent.cpp
index bf22e05f4e9a22f45495bcc1d56c50183fddcda5..c5ef823c73abb3c9e5a2a43a8f708124b0e5cef9 100644
--- a/Source/core/inspector/InspectorPageAgent.cpp
+++ b/Source/core/inspector/InspectorPageAgent.cpp
@@ -536,7 +536,7 @@ void InspectorPageAgent::getCookies(ErrorString*, RefPtr<TypeBuilder::Array<Type
 {
     ListHashSet<Cookie> rawCookiesList;
 
-    for (Frame* frame = mainFrame(); frame; frame = frame->tree()->traverseNext(mainFrame())) {
+    for (Frame* frame = mainFrame(); frame; frame = frame->tree().traverseNext(mainFrame())) {
         Document* document = frame->document();
         Vector<KURL> allURLs = allResourcesURLsForFrame(frame);
         for (Vector<KURL>::const_iterator it = allURLs.begin(); it != allURLs.end(); ++it) {
@@ -558,7 +558,7 @@ void InspectorPageAgent::getCookies(ErrorString*, RefPtr<TypeBuilder::Array<Type
 void InspectorPageAgent::deleteCookie(ErrorString*, const String& cookieName, const String& url)
 {
     KURL parsedURL(ParsedURLString, url);
-    for (Frame* frame = m_page->mainFrame(); frame; frame = frame->tree()->traverseNext(m_page->mainFrame()))
+    for (Frame* frame = m_page->mainFrame(); frame; frame = frame->tree().traverseNext(m_page->mainFrame()))
         WebCore::deleteCookie(frame->document(), parsedURL, cookieName);
 }
 
@@ -632,7 +632,7 @@ void InspectorPageAgent::searchInResources(ErrorString*, const String& text, con
     bool caseSensitive = optionalCaseSensitive ? *optionalCaseSensitive : false;
     OwnPtr<RegularExpression> regex = ContentSearchUtils::createSearchRegex(text, caseSensitive, isRegex);
 
-    for (Frame* frame = m_page->mainFrame(); frame; frame = frame->tree()->traverseNext(m_page->mainFrame())) {
+    for (Frame* frame = m_page->mainFrame(); frame; frame = frame->tree().traverseNext(m_page->mainFrame())) {
         String content;
         Vector<Resource*> allResources = cachedResourcesForFrame(frame);
         for (Vector<Resource*>::const_iterator it = allResources.begin(); it != allResources.end(); ++it) {
@@ -897,7 +897,7 @@ String InspectorPageAgent::loaderId(DocumentLoader* loader)
 
 Frame* InspectorPageAgent::findFrameWithSecurityOrigin(const String& originRawString)
 {
-    for (Frame* frame = m_page->mainFrame(); frame; frame = frame->tree()->traverseNext()) {
+    for (Frame* frame = m_page->mainFrame(); frame; frame = frame->tree().traverseNext()) {
         RefPtr<SecurityOrigin> documentOrigin = frame->document()->securityOrigin();
         if (documentOrigin->toRawString() == originRawString)
             return frame;
@@ -1038,8 +1038,8 @@ PassRefPtr<TypeBuilder::Page::Frame> InspectorPageAgent::buildObjectForFrame(Fra
         .setUrl(urlWithoutFragment(frame->document()->url()).string())
         .setMimeType(frame->loader()->documentLoader()->responseMIMEType())
         .setSecurityOrigin(frame->document()->securityOrigin()->toRawString());
-    if (frame->tree()->parent())
-        frameObject->setParentId(frameId(frame->tree()->parent()));
+    if (frame->tree().parent())
+        frameObject->setParentId(frameId(frame->tree().parent()));
     if (frame->ownerElement()) {
         String name = frame->ownerElement()->getNameAttribute();
         if (name.isEmpty())
@@ -1074,7 +1074,7 @@ PassRefPtr<TypeBuilder::Page::FrameResourceTree> InspectorPageAgent::buildObject
     }
 
     RefPtr<TypeBuilder::Array<TypeBuilder::Page::FrameResourceTree> > childrenArray;
-    for (Frame* child = frame->tree()->firstChild(); child; child = child->tree()->nextSibling()) {
+    for (Frame* child = frame->tree().firstChild(); child; child = child->tree().nextSibling()) {
         if (!childrenArray) {
             childrenArray = TypeBuilder::Array<TypeBuilder::Page::FrameResourceTree>::create();
             result->setChildFrames(childrenArray);