Split the frame tree logic out of HistoryItem

Source/core/loader/FrameLoader.cpp

Index: Source/core/loader/FrameLoader.cpp
diff --git a/Source/core/loader/FrameLoader.cpp b/Source/core/loader/FrameLoader.cpp
index fbf6d9da03013f45873bb4fdc35a980b843ac465..a7033da6620a026a5cb296aa21a9d55ccd7b9d47 100644
--- a/Source/core/loader/FrameLoader.cpp
+++ b/Source/core/loader/FrameLoader.cpp
@@ -70,6 +70,7 @@
 #include "core/loader/ProgressTracker.h"
 #include "core/loader/UniqueIdentifier.h"
 #include "core/loader/appcache/ApplicationCacheHost.h"
+#include "core/page/BackForwardClient.h"
 #include "core/page/Chrome.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/EventHandler.h"
@@ -153,7 +154,7 @@ private:
 FrameLoader::FrameLoader(Frame* frame, FrameLoaderClient* client)
     : m_frame(frame)
     , m_client(client)
-    , m_history(frame)
+    , m_history(frame->page()->history())

[abarth-chromium, 2013/10/29 20:36:58]

Don't we need to clear out m_history when the Frame detaches from the Page? 
Otherwise, the Page can die and we'll have a dangling pointer to the
HistoryController.  Maybe instead of caching a pointer here we should just
always grab the canonical one from the page?

HistoryController* history() const { return m_frame->page() ?
m_frame->page()->history() : 0; }

All the callers of this function need to worry about the case when we're
detached from the page and we've lost the connection to the history controller.

     , m_icon(adoptPtr(new IconController(frame)))
     , m_fetchContext(FrameFetchContext::create(frame))
     , m_mixedContentChecker(frame)
@@ -235,7 +236,7 @@ void FrameLoader::stopLoading()
 
 bool FrameLoader::closeURL()
 {
-    history()->saveDocumentAndScrollState();
+    history()->saveDocumentAndScrollState(m_frame);
 
     // Should only send the pagehide event here if the current document exists.
     if (m_frame->document())
@@ -328,8 +329,9 @@ void FrameLoader::didBeginDocument(bool dispatch)
     m_isComplete = false;
     m_frame->document()->setReadyState(Document::Loading);
 
-    if (history()->currentItem() && m_loadType == FrameLoadTypeBackForward)
-        m_frame->document()->statePopped(history()->currentItem()->stateObject());
+    if (history()->currentItem(m_frame) && m_loadType == FrameLoadTypeBackForward) {
+        m_frame->document()->statePopped(history()->currentItem(m_frame)->stateObject());
+    }
 
     if (dispatch)
         dispatchDidClearWindowObjectsInAllWorlds();
@@ -357,7 +359,7 @@ void FrameLoader::didBeginDocument(bool dispatch)
         }
     }
 
-    history()->restoreDocumentState();
+    history()->restoreDocumentState(m_frame);
 }
 
 void FrameLoader::finishedParsing()
@@ -537,14 +539,14 @@ void FrameLoader::updateForSameDocumentNavigation(const KURL& newURL, SameDocume
     // replaceRequestURLForSameDocumentNavigation(), since we add based on
     // the current request.
     if (updateBackForwardList == UpdateBackForwardList)
-        history()->updateBackForwardListForFragmentScroll();
+        history()->updateBackForwardListForFragmentScroll(m_frame);
 
     if (sameDocumentNavigationSource == SameDocumentNavigationDefault)
-        history()->updateForSameDocumentNavigation();
+        history()->updateForSameDocumentNavigation(m_frame);
     else if (sameDocumentNavigationSource == SameDocumentNavigationPushState)
-        history()->pushState(data, newURL.string());
+        history()->pushState(m_frame, data, newURL.string());
     else if (sameDocumentNavigationSource == SameDocumentNavigationReplaceState)
-        history()->replaceState(data, newURL.string());
+        history()->replaceState(m_frame, data, newURL.string());
     else
         ASSERT_NOT_REACHED();
 
@@ -622,16 +624,6 @@ void FrameLoader::started()
 
 void FrameLoader::prepareForHistoryNavigation()
 {
-    // If there is no currentItem, but we still want to engage in
-    // history navigation we need to manufacture one, and update
-    // the state machine of this frame to impersonate having
-    // loaded it.
-    RefPtr<HistoryItem> currentItem = history()->currentItem();
-    if (!currentItem) {
-        insertDummyHistoryItem();
-        ASSERT(stateMachine()->isDisplayingInitialEmptyDocument());
-        stateMachine()->advanceTo(FrameLoaderStateMachine::CommittedFirstRealLoad);
-    }
 }
 
 void FrameLoader::setReferrerForFrameRequest(ResourceRequest& request, ShouldSendReferrer shouldSendReferrer)
@@ -665,7 +657,7 @@ FrameLoadType FrameLoader::determineFrameLoadType(const FrameLoadRequest& reques
 {
     if (m_frame->tree().parent() && !m_stateMachine.startedFirstRealLoad())
         return FrameLoadTypeInitialInChildFrame;
-    if (!m_frame->tree().parent() && !history()->currentItem())
+    if (!m_frame->tree().parent() && !m_frame->page()->backForward().backForwardListCount())
         return FrameLoadTypeStandard;
     if (request.resourceRequest().cachePolicy() == ReloadIgnoringCacheData)
         return FrameLoadTypeReload;
@@ -786,9 +778,6 @@ void FrameLoader::reload(ReloadPolicy reloadPolicy, const KURL& overrideURL, con
     if (!documentLoader)
         return;
 
-    if (m_state == FrameStateProvisional)
-        insertDummyHistoryItem();
-
     ResourceRequest request = documentLoader->request();
     // FIXME: We need to reset cache policy to prevent it from being incorrectly propagted to the reload.
     // Do we need to propagate anything other than the url?
@@ -907,7 +896,7 @@ void FrameLoader::commitProvisionalLoad()
     if (isLoadingMainFrame())
         m_frame->page()->chrome().client().needTouchEvents(false);
 
-    history()->updateForCommit();
+    history()->updateForCommit(m_frame);
     m_client->transitionToCommittedForNewPage();
 
     m_frame->navigationScheduler().cancel();
@@ -1023,7 +1012,7 @@ void FrameLoader::checkLoadCompleteForThisFrame()
     // If the user had a scroll point, scroll to it, overriding the anchor point if any.
     if (m_frame->page()) {
         if (isBackForwardLoadType(m_loadType) || m_loadType == FrameLoadTypeReload || m_loadType == FrameLoadTypeReloadFromOrigin)
-            history()->restoreScrollPositionAndViewState();
+            history()->restoreScrollPositionAndViewState(m_frame);
     }
 
     if (!m_stateMachine.committedFirstRealDocumentLoad())
@@ -1042,7 +1031,7 @@ void FrameLoader::checkLoadCompleteForThisFrame()
 void FrameLoader::didFirstLayout()
 {
     if (m_frame->page() && isBackForwardLoadType(m_loadType))
-        history()->restoreScrollPositionAndViewState();
+        history()->restoreScrollPositionAndViewState(m_frame);
 }
 
 void FrameLoader::detachChildren()
@@ -1249,7 +1238,7 @@ void FrameLoader::checkNavigationPolicyAndContinueFragmentScroll(const Navigatio
             m_provisionalDocumentLoader->detachFromFrame();
         m_provisionalDocumentLoader = 0;
     }
-    history()->setProvisionalItem(0);
+    history()->clearProvisionalEntry();
     loadInSameDocument(request.url(), 0, isNewNavigation);
 }
 
@@ -1489,9 +1478,7 @@ bool FrameLoader::shouldInterruptLoadForXFrameOptions(const String& content, con
 
 bool FrameLoader::shouldTreatURLAsSameAsCurrent(const KURL& url) const
 {
-    if (!history()->currentItem())
-        return false;
-    return url == history()->currentItem()->url() || url == history()->currentItem()->originalURL();
+    return url == m_frame->document()->url() || url == m_documentLoader->originalURL();
 }
 
 bool FrameLoader::shouldTreatURLAsSrcdocDocument(const KURL& url) const
@@ -1535,19 +1522,13 @@ Frame* FrameLoader::findFrameForNavigation(const AtomicString& name, Document* a
     return frame;
 }
 
-void FrameLoader::loadHistoryItem(HistoryItem* item)
+void FrameLoader::loadHistoryItem(HistoryItem* item, HistoryLoadType historyLoadType)
 {
-    HistoryItem* currentItem = history()->currentItem();
-
-    if (currentItem && item->shouldDoSameDocumentNavigationTo(currentItem)) {
-        history()->setCurrentItem(item);
+    if (historyLoadType == HistorySameDocumentLoad) {
         loadInSameDocument(item->url(), item->stateObject(), false);
         return;
     }
 
-    // Remember this item so we can traverse any child items as child frames load
-    history()->setProvisionalItem(item);
-
     RefPtr<FormData> formData = item->formData();
     ResourceRequest request(item->url());
     request.setHTTPReferrer(item->referrer());
@@ -1564,8 +1545,6 @@ void FrameLoader::loadHistoryItem(HistoryItem* item)
 
 void FrameLoader::insertDummyHistoryItem()
 {
-    RefPtr<HistoryItem> currentItem = HistoryItem::create();
-    history()->setCurrentItem(currentItem.get());
 }
 
 void FrameLoader::dispatchDocumentElementAvailable()