Bug 1485279 - Merge nsISHContainer into nsISHEntry. r=qdot

nsSHEntry is the only class that instantiates those two interfaces, so the
separation is not useful. This lets us remove numerous pointless QIs.

--HG--
extra : rebase_source : 570b7ade669fb89a789184198bec9da186c5f1d3

browser/components/sessionstore/test/browser_687710_2.js

@@ -30,13 +30,8 @@ add_task(async function test() {
   await promiseTabState(tab, state);
   await ContentTask.spawn(tab.linkedBrowser, null, function() {
     function compareEntries(i, j, history) {
-      let e1 = history.getEntryAtIndex(i, false)
-                      .QueryInterface(Ci.nsISHEntry)
-                      .QueryInterface(Ci.nsISHContainer);
-
-      let e2 = history.getEntryAtIndex(j, false)
-                      .QueryInterface(Ci.nsISHEntry)
-                      .QueryInterface(Ci.nsISHContainer);
+      let e1 = history.getEntryAtIndex(i, false);
+      let e2 = history.getEntryAtIndex(j, false);
 
       ok(e1.sharesDocumentWith(e2),
          `${i} should share doc with ${j}`);

browser/components/sessionstore/test/browser_705597.js

@@ -25,7 +25,6 @@ function test() {
   promiseTabState(tab, tabState).then(() => {
     let sessionHistory = browser.sessionHistory;
     let entry = sessionHistory.legacySHistory.getEntryAtIndex(0, false);
-    entry.QueryInterface(Ci.nsISHContainer);
 
     whenChildCount(entry, 1, function() {
       whenChildCount(entry, 2, function() {

browser/components/sessionstore/test/browser_707862.js

@@ -25,7 +25,6 @@ function test() {
   promiseTabState(tab, tabState).then(() => {
     let sessionHistory = browser.sessionHistory;
     let entry = sessionHistory.legacySHistory.getEntryAtIndex(0, false);
-    entry.QueryInterface(Ci.nsISHContainer);
 
     whenChildCount(entry, 1, function() {
       whenChildCount(entry, 2, function() {

docshell/base/nsDocShell.cpp

@@ -117,7 +117,6 @@
 #include "nsISecurityUITelemetry.h"
 #include "nsISeekableStream.h"
 #include "nsISelectionDisplay.h"
-#include "nsISHContainer.h"
 #include "nsISHEntry.h"
 #include "nsISHistory.h"
 #include "nsISHistoryInternal.h"
@@ -1069,10 +1068,9 @@ nsDocShell::FirePageHideNotificationInternal(bool aIsUnload,
     // If the document is unloading, remove all dynamic subframe entries.
     if (aIsUnload && !aSkipCheckingDynEntries) {
       RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
-      nsCOMPtr<nsISHContainer> container(do_QueryInterface(mOSHE));
-      if (rootSH && container) {
+      if (rootSH && mOSHE) {
         int32_t index = rootSH->Index();
-        rootSH->LegacySHistoryInternal()->RemoveDynEntries(index, container);
+        rootSH->LegacySHistoryInternal()->RemoveDynEntries(index, mOSHE);
       }
     }
 
@@ -3729,13 +3727,10 @@ nsDocShell::GetChildSHEntry(int32_t aChildOffset, nsISHEntry** aResult)
       return rv;
     }
 
-    nsCOMPtr<nsISHContainer> container(do_QueryInterface(mLSHE));
-    if (container) {
-      // Get the child subframe from session history.
-      rv = container->GetChildAt(aChildOffset, aResult);
-      if (*aResult) {
-        (*aResult)->SetLoadType(loadType);
-      }
+    // Get the child subframe from session history.
+    rv = mLSHE->GetChildAt(aChildOffset, aResult);
+    if (*aResult) {
+      (*aResult)->SetLoadType(loadType);
     }
   }
   return rv;
@@ -3752,17 +3747,13 @@ nsDocShell::AddChildSHEntry(nsISHEntry* aCloneRef, nsISHEntry* aNewEntry,
     /* You get here if you are currently building a
      * hierarchy ie.,you just visited a frameset page
      */
-    nsCOMPtr<nsISHContainer> container(do_QueryInterface(mLSHE, &rv));
-    if (container) {
-      if (NS_FAILED(container->ReplaceChild(aNewEntry))) {
-        rv = container->AddChild(aNewEntry, aChildOffset);
-      }
+    if (NS_FAILED(mLSHE->ReplaceChild(aNewEntry))) {
+      rv = mLSHE->AddChild(aNewEntry, aChildOffset);
     }
   } else if (!aCloneRef) {
     /* This is an initial load in some subframe.  Just append it if we can */
-    nsCOMPtr<nsISHContainer> container(do_QueryInterface(mOSHE, &rv));
-    if (container) {
-      rv = container->AddChild(aNewEntry, aChildOffset);
+    if (mOSHE) {
+      rv = mOSHE->AddChild(aNewEntry, aChildOffset);
     }
   } else {
     rv = AddChildSHEntryInternal(aCloneRef, aNewEntry, aChildOffset,
@@ -3997,18 +3988,17 @@ nsDocShell::GetDeviceSizeIsPageSize(bool* aValue)
 void
 nsDocShell::ClearFrameHistory(nsISHEntry* aEntry)
 {
-  nsCOMPtr<nsISHContainer> shcontainer = do_QueryInterface(aEntry);
   RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
-  if (!rootSH || !shcontainer) {
+  if (!rootSH || !aEntry) {
     return;
   }
 
   int32_t count = 0;
-  shcontainer->GetChildCount(&count);
+  aEntry->GetChildCount(&count);
   AutoTArray<nsID, 16> ids;
   for (int32_t i = 0; i < count; ++i) {
     nsCOMPtr<nsISHEntry> child;
-    shcontainer->GetChildAt(i, getter_AddRefs(child));
+    aEntry->GetChildAt(i, getter_AddRefs(child));
     if (child) {
       ids.AppendElement(child->DocshellID());
     }
@@ -12044,15 +12034,14 @@ nsDocShell::AddToSessionHistory(nsIURI* aURI, nsIChannel* aChannel,
       root != static_cast<nsIDocShellTreeItem*>(this)) {
     // This is a subframe
     entry = mOSHE;
-    nsCOMPtr<nsISHContainer> shContainer(do_QueryInterface(entry));
-    if (shContainer) {
+    if (entry) {
       int32_t childCount = 0;
-      shContainer->GetChildCount(&childCount);
+      entry->GetChildCount(&childCount);
       // Remove all children of this entry
       for (int32_t i = childCount - 1; i >= 0; i--) {
         nsCOMPtr<nsISHEntry> child;
-        shContainer->GetChildAt(i, getter_AddRefs(child));
-        shContainer->RemoveChild(child);
+        entry->GetChildAt(i, getter_AddRefs(child));
+        entry->RemoveChild(child);
       }
       entry->AbandonBFCacheEntry();
     }

docshell/shistory/moz.build

@@ -6,7 +6,6 @@
 
 XPIDL_SOURCES += [
     'nsIBFCacheEntry.idl',
-    'nsISHContainer.idl',
     'nsISHEntry.idl',
     'nsISHistory.idl',
     'nsISHistoryInternal.idl',

docshell/shistory/nsISHContainer.idl

@@ -1,49 +0,0 @@
-/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
- *
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include "nsISupports.idl"
-
-interface nsISHEntry;
-
-/**
- * The nsISHEntryContainer. The interface to access child entries
- * of an nsISHEntry.
- * 
- */
-
-[scriptable, uuid(67dd0357-8372-4122-bff6-217435e8b7e4)]
-interface nsISHContainer : nsISupports
-{
-	/**
-     * The current number of nsISHEntries which are immediate children of the 
-	 * current SHEntry
-     */
-	readonly attribute long childCount;
-
-	/**
-	 * Add a new child SHEntry.  If offset is -1 adds to the end of the list.
-	 */
-	void AddChild(in nsISHEntry child, in long offset);
-
-	/**
-	 * Removes a child SHEntry
-	 */
-	void RemoveChild(in nsISHEntry child);
-
-	/**
-	 * Get child at an index
-	 */
-	nsISHEntry GetChildAt(in long index);
-
-	/**
-	 * Replaces a child which is for the same docshell as aNewChild
-	 * with aNewChild.
-	 * @throw if nothing was replaced.
-	 */
-	void ReplaceChild(in nsISHEntry aNewChild);
-
-};
-

docshell/shistory/nsISHEntry.idl

@@ -4,10 +4,9 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
- * The interface to nsISHentry. Each document or subframe in 
+ * The interface to nsISHentry. Each document or subframe in
  * Session History will have a nsISHEntry associated with it which will
  * hold all information required to recreate the document from history
- * 
  */
 
 #include "nsISupports.idl"
@@ -180,7 +179,7 @@ interface nsISHEntry : nsISupports
      * attribute to indicate the content-type of the document that this
      * is a session history entry for
      */
-    attribute ACString contentType; 
+    attribute ACString contentType;
 
     /**
      * If we created this SHEntry via history.pushState or modified it via
@@ -194,7 +193,7 @@ interface nsISHEntry : nsISupports
      *
      */
     attribute boolean URIWasModified;
- 
+
     /** Set/Get scrollers' positon in anchored pages */
     void setScrollPosition(in long x, in long y);
     void getScrollPosition(out long x, out long y);
@@ -373,6 +372,34 @@ interface nsISHEntry : nsISupports
      */
     [noscript, notxpcom]
     nsSHEntryShared getSharedState();
+
+    /**
+     * The current number of nsISHEntries which are immediate children of this
+     * SHEntry.
+     */
+    readonly attribute long childCount;
+
+    /**
+     * Add a new child SHEntry. If offset is -1 adds to the end of the list.
+     */
+    void AddChild(in nsISHEntry aChild, in long aOffset);
+
+    /**
+     * Remove a child SHEntry.
+     */
+    void RemoveChild(in nsISHEntry aChild);
+
+    /**
+     * Get child at an index.
+     */
+    nsISHEntry GetChildAt(in long aIndex);
+
+    /**
+     * Replaces a child which is for the same docshell as aNewChild
+     * with aNewChild.
+     * @throw if nothing was replaced.
+     */
+    void ReplaceChild(in nsISHEntry aNewChild);
 };
 
 %{ C++
@@ -382,6 +409,5 @@ interface nsISHEntry : nsISupports
 
 #define NS_SHENTRY_CONTRACTID \
     "@mozilla.org/browser/session-history-entry;1"
-
 %}
 

docshell/shistory/nsISHistoryInternal.idl

@@ -6,7 +6,6 @@
 #include "nsISupports.idl"
 
 interface nsIBFCacheEntry;
-interface nsISHContainer;
 interface nsISHEntry;
 interface nsISHistoryListener;
 interface nsISHTransaction;
@@ -106,13 +105,13 @@ interface nsISHistoryInternal: nsISupports
     * @param aIndex
     *        Index to remove dynamic entries from. It will be passed to
     *        RemoveEntries as aStartIndex.
-    * @param aContainer (optional)
-    *        The container to start looking for dynamic entries. Only the
-    *        dynamic descendants of the container will be removed. If not given,
+    * @param aEntry (optional)
+    *        The entry to start looking in for dynamic entries. Only the
+    *        dynamic descendants of the entry will be removed. If not given,
     *        all dynamic entries at the index will be removed.
     */
    [noscript, notxpcom] void RemoveDynEntries(in long aIndex,
-                                              in nsISHContainer aContainer);
+                                              in nsISHEntry aEntry);
 
    /**
     * Similar to RemoveDynEntries, but instead of specifying an index, use the

docshell/shistory/nsSHEntry.cpp

@@ -76,7 +76,7 @@ nsSHEntry::~nsSHEntry()
   }
 }
 
-NS_IMPL_ISUPPORTS(nsSHEntry, nsISHContainer, nsISHEntry)
+NS_IMPL_ISUPPORTS(nsSHEntry, nsISHEntry)
 
 NS_IMETHODIMP
 nsSHEntry::SetScrollPosition(int32_t aX, int32_t aY)

docshell/shistory/nsSHEntry.h

@@ -9,7 +9,6 @@
 
 #include "nsCOMArray.h"
 #include "nsCOMPtr.h"
-#include "nsISHContainer.h"
 #include "nsISHEntry.h"
 #include "nsString.h"
 
@@ -19,8 +18,7 @@ class nsSHEntryShared;
 class nsIInputStream;
 class nsIURI;
 
-class nsSHEntry final : public nsISHEntry,
-                        public nsISHContainer
+class nsSHEntry final : public nsISHEntry
 {
 public:
   nsSHEntry();
@@ -28,7 +26,6 @@ public:
 
   NS_DECL_ISUPPORTS
   NS_DECL_NSISHENTRY
-  NS_DECL_NSISHCONTAINER
 
   void DropPresentationState();
 

docshell/shistory/nsSHistory.cpp

@@ -17,7 +17,6 @@
 #include "nsIDocShellTreeItem.h"
 #include "nsILayoutHistoryState.h"
 #include "nsIObserverService.h"
-#include "nsISHContainer.h"
 #include "nsISHEntry.h"
 #include "nsISHistoryListener.h"
 #include "nsISHTransaction.h"
@@ -233,8 +232,7 @@ nsSHistory::EvictContentViewerForTransaction(nsISHTransaction* aTrans)
   int32_t index = -1;
   GetIndexOfEntry(entry, &index);
   if (index != -1) {
-    nsCOMPtr<nsISHContainer> container(do_QueryInterface(entry));
-    RemoveDynEntries(index, container);
+    RemoveDynEntries(index, entry);
   }
 }
 
@@ -419,16 +417,11 @@ nsSHistory::WalkHistoryEntries(nsISHEntry* aRootEntry,
 {
   NS_ENSURE_TRUE(aRootEntry, NS_ERROR_FAILURE);
 
-  nsCOMPtr<nsISHContainer> container(do_QueryInterface(aRootEntry));
-  if (!container) {
-    return NS_ERROR_FAILURE;
-  }
-
   int32_t childCount;
-  container->GetChildCount(&childCount);
+  aRootEntry->GetChildCount(&childCount);
   for (int32_t i = 0; i < childCount; i++) {
     nsCOMPtr<nsISHEntry> childEntry;
-    container->GetChildAt(i, getter_AddRefs(childEntry));
+    aRootEntry->GetChildAt(i, getter_AddRefs(childEntry));
     if (!childEntry) {
       // childEntry can be null for valid reasons, for example if the
       // docshell at index i never loaded anything useful.
@@ -493,10 +486,9 @@ nsSHistory::CloneAndReplaceChild(nsISHEntry* aEntry,
   uint32_t cloneID = data->cloneID;
   nsISHEntry* replaceEntry = data->replaceEntry;
 
-  nsCOMPtr<nsISHContainer> container = do_QueryInterface(data->destTreeParent);
   if (!aEntry) {
-    if (container) {
-      container->AddChild(nullptr, aEntryIndex);
+    if (data->destTreeParent) {
+      data->destTreeParent->AddChild(nullptr, aEntryIndex);
     }
     return NS_OK;
   }
@@ -528,8 +520,8 @@ nsSHistory::CloneAndReplaceChild(nsISHEntry* aEntry,
     aShell->SwapHistoryEntries(aEntry, dest);
   }
 
-  if (container) {
-    container->AddChild(dest, aEntryIndex);
+  if (data->destTreeParent) {
+    data->destTreeParent->AddChild(dest, aEntryIndex);
   }
 
   data->resultEntry = dest;
@@ -570,9 +562,8 @@ nsSHistory::SetChildHistoryEntry(nsISHEntry* aEntry, nsDocShell* aShell,
   nsISHEntry* destTreeRoot = data->destTreeRoot;
 
   nsCOMPtr<nsISHEntry> destEntry;
-  nsCOMPtr<nsISHContainer> container = do_QueryInterface(data->destTreeParent);
 
-  if (container) {
+  if (data->destTreeParent) {
     // aEntry is a clone of some child of destTreeParent, but since the
     // trees aren't necessarily in sync, we'll have to locate it.
     // Note that we could set aShell's entry to null if we don't find a
@@ -583,14 +574,14 @@ nsSHistory::SetChildHistoryEntry(nsISHEntry* aEntry, nsDocShell* aShell,
 
     // First look at the given index, since this is the common case.
     nsCOMPtr<nsISHEntry> entry;
-    container->GetChildAt(aEntryIndex, getter_AddRefs(entry));
+    data->destTreeParent->GetChildAt(aEntryIndex, getter_AddRefs(entry));
     if (entry && NS_SUCCEEDED(entry->GetID(&id)) && id == targetID) {
       destEntry.swap(entry);
     } else {
       int32_t childCount;
-      container->GetChildCount(&childCount);
+      data->destTreeParent->GetChildCount(&childCount);
       for (int32_t i = 0; i < childCount; ++i) {
-        container->GetChildAt(i, getter_AddRefs(entry));
+        data->destTreeParent->GetChildAt(i, getter_AddRefs(entry));
         if (!entry) {
           continue;
         }
@@ -1521,15 +1512,15 @@ nsSHistory::GloballyEvictAllContentViewers()
 }
 
 void
-GetDynamicChildren(nsISHContainer* aContainer,
+GetDynamicChildren(nsISHEntry* aEntry,
                    nsTArray<nsID>& aDocshellIDs,
                    bool aOnlyTopLevelDynamic)
 {
   int32_t count = 0;
-  aContainer->GetChildCount(&count);
+  aEntry->GetChildCount(&count);
   for (int32_t i = 0; i < count; ++i) {
     nsCOMPtr<nsISHEntry> child;
-    aContainer->GetChildAt(i, getter_AddRefs(child));
+    aEntry->GetChildAt(i, getter_AddRefs(child));
     if (child) {
       bool dynAdded = false;
       child->IsDynamicallyAdded(&dynAdded);
@@ -1538,42 +1529,30 @@ GetDynamicChildren(nsISHContainer* aContainer,
         aDocshellIDs.AppendElement(docshellID);
       }
       if (!dynAdded || !aOnlyTopLevelDynamic) {
-        nsCOMPtr<nsISHContainer> childAsContainer = do_QueryInterface(child);
-        if (childAsContainer) {
-          GetDynamicChildren(childAsContainer, aDocshellIDs,
-                             aOnlyTopLevelDynamic);
-        }
+        GetDynamicChildren(child, aDocshellIDs, aOnlyTopLevelDynamic);
       }
     }
   }
 }
 
 bool
-RemoveFromSessionHistoryContainer(nsISHContainer* aContainer,
-                                  nsTArray<nsID>& aDocshellIDs)
+RemoveFromSessionHistoryEntry(nsISHEntry* aRoot, nsTArray<nsID>& aDocshellIDs)
 {
-  nsCOMPtr<nsISHEntry> root = do_QueryInterface(aContainer);
-  NS_ENSURE_TRUE(root, false);
-
   bool didRemove = false;
   int32_t childCount = 0;
-  aContainer->GetChildCount(&childCount);
+  aRoot->GetChildCount(&childCount);
   for (int32_t i = childCount - 1; i >= 0; --i) {
     nsCOMPtr<nsISHEntry> child;
-    aContainer->GetChildAt(i, getter_AddRefs(child));
+    aRoot->GetChildAt(i, getter_AddRefs(child));
     if (child) {
       nsID docshelldID = child->DocshellID();
       if (aDocshellIDs.Contains(docshelldID)) {
         didRemove = true;
-        aContainer->RemoveChild(child);
+        aRoot->RemoveChild(child);
       } else {
-        nsCOMPtr<nsISHContainer> container = do_QueryInterface(child);
-        if (container) {
-          bool childRemoved =
-            RemoveFromSessionHistoryContainer(container, aDocshellIDs);
-          if (childRemoved) {
-            didRemove = true;
-          }
+        bool childRemoved = RemoveFromSessionHistoryEntry(child, aDocshellIDs);
+        if (childRemoved) {
+          didRemove = true;
         }
       }
     }
@@ -1585,10 +1564,9 @@ bool
 RemoveChildEntries(nsISHistory* aHistory, int32_t aIndex,
                    nsTArray<nsID>& aEntryIDs)
 {
-  nsCOMPtr<nsISHEntry> rootHE;
-  aHistory->GetEntryAtIndex(aIndex, false, getter_AddRefs(rootHE));
-  nsCOMPtr<nsISHContainer> root = do_QueryInterface(rootHE);
-  return root ? RemoveFromSessionHistoryContainer(root, aEntryIDs) : false;
+  nsCOMPtr<nsISHEntry> root;
+  aHistory->GetEntryAtIndex(aIndex, false, getter_AddRefs(root));
+  return root ? RemoveFromSessionHistoryEntry(root, aEntryIDs) : false;
 }
 
 bool
@@ -1607,17 +1585,15 @@ IsSameTree(nsISHEntry* aEntry1, nsISHEntry* aEntry2)
     return false;
   }
 
-  nsCOMPtr<nsISHContainer> container1 = do_QueryInterface(aEntry1);
-  nsCOMPtr<nsISHContainer> container2 = do_QueryInterface(aEntry2);
   int32_t count1, count2;
-  container1->GetChildCount(&count1);
-  container2->GetChildCount(&count2);
+  aEntry1->GetChildCount(&count1);
+  aEntry2->GetChildCount(&count2);
   // We allow null entries in the end of the child list.
   int32_t count = std::max(count1, count2);
   for (int32_t i = 0; i < count; ++i) {
     nsCOMPtr<nsISHEntry> child1, child2;
-    container1->GetChildAt(i, getter_AddRefs(child1));
-    container2->GetChildAt(i, getter_AddRefs(child2));
+    aEntry1->GetChildAt(i, getter_AddRefs(child1));
+    aEntry2->GetChildAt(i, getter_AddRefs(child2));
     if (!IsSameTree(child1, child2)) {
       return false;
     }
@@ -1722,19 +1698,17 @@ nsSHistory::RemoveEntries(nsTArray<nsID>& aIDs, int32_t aStartIndex)
 }
 
 void
-nsSHistory::RemoveDynEntries(int32_t aIndex, nsISHContainer* aContainer)
+nsSHistory::RemoveDynEntries(int32_t aIndex, nsISHEntry* aEntry)
 {
   // Remove dynamic entries which are at the index and belongs to the container.
-  nsCOMPtr<nsISHContainer> container(aContainer);
-  if (!container) {
-    nsCOMPtr<nsISHEntry> entry;
+  nsCOMPtr<nsISHEntry> entry(aEntry);
+  if (!entry) {
     GetEntryAtIndex(aIndex, false, getter_AddRefs(entry));
-    container = do_QueryInterface(entry);
   }
 
-  if (container) {
+  if (entry) {
     AutoTArray<nsID, 16> toBeRemovedEntries;
-    GetDynamicChildren(container, toBeRemovedEntries, true);
+    GetDynamicChildren(entry, toBeRemovedEntries, true);
     if (toBeRemovedEntries.Length()) {
       RemoveEntries(toBeRemovedEntries, aIndex);
     }
@@ -1750,8 +1724,7 @@ nsSHistory::RemoveDynEntriesForBFCacheEntry(nsIBFCacheEntry* aEntry)
   if (trans) {
     nsCOMPtr<nsISHEntry> entry;
     trans->GetSHEntry(getter_AddRefs(entry));
-    nsCOMPtr<nsISHContainer> container(do_QueryInterface(entry));
-    RemoveDynEntries(index, container);
+    RemoveDynEntries(index, entry);
   }
 }
 
@@ -1967,15 +1940,9 @@ nsSHistory::LoadDifferingEntries(nsISHEntry* aPrevEntry, nsISHEntry* aNextEntry,
   int32_t pcnt = 0;
   int32_t ncnt = 0;
   int32_t dsCount = 0;
-  nsCOMPtr<nsISHContainer> prevContainer(do_QueryInterface(aPrevEntry));
-  nsCOMPtr<nsISHContainer> nextContainer(do_QueryInterface(aNextEntry));
 
-  if (!prevContainer || !nextContainer) {
-    return NS_ERROR_FAILURE;
-  }
-
-  prevContainer->GetChildCount(&pcnt);
-  nextContainer->GetChildCount(&ncnt);
+  aPrevEntry->GetChildCount(&pcnt);
+  aNextEntry->GetChildCount(&ncnt);
   aParent->GetChildCount(&dsCount);
 
   // Create an array for child docshells.
@@ -1993,7 +1960,7 @@ nsSHistory::LoadDifferingEntries(nsISHEntry* aPrevEntry, nsISHEntry* aNextEntry,
   for (int32_t i = 0; i < ncnt; ++i) {
     // First get an entry which may cause a new page to be loaded.
     nsCOMPtr<nsISHEntry> nChild;
-    nextContainer->GetChildAt(i, getter_AddRefs(nChild));
+    aNextEntry->GetChildAt(i, getter_AddRefs(nChild));
     if (!nChild) {
       continue;
     }
@@ -2019,7 +1986,7 @@ nsSHistory::LoadDifferingEntries(nsISHEntry* aPrevEntry, nsISHEntry* aNextEntry,
     nsCOMPtr<nsISHEntry> pChild;
     for (int32_t k = 0; k < pcnt; ++k) {
       nsCOMPtr<nsISHEntry> child;
-      prevContainer->GetChildAt(k, getter_AddRefs(child));
+      aPrevEntry->GetChildAt(k, getter_AddRefs(child));
       if (child) {
         nsID dID = child->DocshellID();
         if (dID == docshellID) {

docshell/test/navigation/test_bug1375833.html

@@ -50,9 +50,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=1375833
       is(newFrameDocShellId, frameDocShellId, "check docshell ID remains after reload");
 
       let entry = shistory.legacySHistory.getEntryAtIndex(shistory.index, false);
-      let frameEntry = SpecialPowers.wrap(entry)
-                       .QueryInterface(SpecialPowers.Ci.nsISHContainer)
-                       .GetChildAt(0);
+      let frameEntry = entry.GetChildAt(0);
       is(String(frameEntry.docshellID), frameDocShellId, "check newly added shentry uses the same docshell ID");
 
       webNav.goBack();

docshell/test/test_bug590573.html

@@ -111,7 +111,6 @@ function dumpSHistory(theWindow)
   for (let i = 0; i < sh.count; i++) {
     let shentry = sh.legacySHistory.getEntryAtIndex(i, false);
     dump(" " + i + ": " + shentry.URI.spec + '\n');
-    shentry.QueryInterface(SpecialPowers.Ci.nsISHContainer);
     for (let j = 0; j < shentry.childCount; j++) {
       let child = shentry.GetChildAt(j);
       dump("   child " + j + ": " + child.URI.spec + '\n');

dom/base/nsCCUncollectableMarker.cpp

@@ -17,7 +17,6 @@
 #include "nsIWebNavigation.h"
 #include "nsISHistory.h"
 #include "nsISHEntry.h"
-#include "nsISHContainer.h"
 #include "nsIWindowWatcher.h"
 #include "mozilla/Services.h"
 #include "nsIXULWindow.h"
@@ -233,15 +232,13 @@ MarkSHEntry(nsISHEntry* aSHEntry, bool aCleanupJS)
     MarkDocShell(child, aCleanupJS);
   }
 
-  nsCOMPtr<nsISHContainer> shCont = do_QueryInterface(aSHEntry);
   int32_t count;
-  shCont->GetChildCount(&count);
+  aSHEntry->GetChildCount(&count);
   for (i = 0; i < count; ++i) {
     nsCOMPtr<nsISHEntry> childEntry;
-    shCont->GetChildAt(i, getter_AddRefs(childEntry));
+    aSHEntry->GetChildAt(i, getter_AddRefs(childEntry));
     MarkSHEntry(childEntry, aCleanupJS);
   }
-
 }
 
 void

toolkit/modules/sessionstore/SessionHistory.jsm

@@ -228,10 +228,6 @@ var SessionHistoryInternal = {
       entry.structuredCloneVersion = shEntry.stateData.formatVersion;
     }
 
-    if (!(shEntry instanceof Ci.nsISHContainer)) {
-      return entry;
-    }
-
     if (shEntry.childCount > 0 && !shEntry.hasDynamicallyAddedChild()) {
       let children = [];
       for (let i = 0; i < shEntry.childCount; i++) {
@@ -457,7 +453,7 @@ var SessionHistoryInternal = {
       shEntry.principalToInherit = Utils.deserializePrincipal(entry.principalToInherit_base64);
     }
 
-    if (entry.children && shEntry instanceof Ci.nsISHContainer) {
+    if (entry.children) {
       for (var i = 0; i < entry.children.length; i++) {
         // XXXzpao Wallpaper patch for bug 514751
         if (!entry.children[i].url)