Create a NavigationEntry for the initial blank page.

content/browser/frame_host/navigation_controller_impl.cc

Index: content/browser/frame_host/navigation_controller_impl.cc
diff --git a/content/browser/frame_host/navigation_controller_impl.cc b/content/browser/frame_host/navigation_controller_impl.cc
index 8a0c2071d62e92317fc55811882780ab5f859997..e3256686dd802b6414302d68431d47b65605eecd 100644
--- a/content/browser/frame_host/navigation_controller_impl.cc
+++ b/content/browser/frame_host/navigation_controller_impl.cc
@@ -223,10 +223,10 @@ NavigationControllerImpl::NavigationControllerImpl(
     NavigationControllerDelegate* delegate,
     BrowserContext* browser_context)
     : browser_context_(browser_context),
-      pending_entry_(NULL),
+      pending_entry_(nullptr),
       failed_pending_entry_id_(0),
       failed_pending_entry_should_replace_(false),
-      last_committed_entry_index_(-1),
+      last_committed_entry_index_(0),
       pending_entry_index_(-1),
       transient_entry_index_(-1),
       delegate_(delegate),
@@ -263,11 +263,13 @@ void NavigationControllerImpl::Restore(
     RestoreType type,
     ScopedVector<NavigationEntry>* entries) {
   // Verify that this controller is unused and that the input is valid.
-  DCHECK(GetEntryCount() == 0 && !GetPendingEntry());
+  DCHECK(IsInitialBlankNavigation() && GetEntryCount() == 1 &&
+         !GetPendingEntry());
   DCHECK(selected_navigation >= 0 &&
          selected_navigation < static_cast<int>(entries->size()));
 
   needs_reload_ = true;
+  entries_.clear();
   for (size_t i = 0; i < entries->size(); ++i) {
     NavigationEntryImpl* entry =
         NavigationEntryImpl::FromNavigationEntry((*entries)[i]);
@@ -402,6 +404,14 @@ bool NavigationControllerImpl::IsInitialNavigation() const {
   return is_initial_navigation_;
 }
 
+bool NavigationControllerImpl::IsInitialBlankNavigation() const {
+  // Only return true if the initial navigation is not marked as a restore, as
+  // it is during a clone.
+  return IsInitialNavigation() &&
+      GetEntryCount() == 1 &&
+      GetEntryAtIndex(0)->restore_type() == NavigationEntryImpl::RESTORE_NONE;
+}
+
 NavigationEntryImpl* NavigationControllerImpl::GetEntryWithPageID(
   SiteInstance* instance, int32 page_id) const {
   int index = GetEntryIndexWithPageID(instance, page_id);
@@ -483,8 +493,8 @@ int NavigationControllerImpl::GetCurrentEntryIndex() const {
 }
 
 NavigationEntryImpl* NavigationControllerImpl::GetLastCommittedEntry() const {
-  if (last_committed_entry_index_ == -1)
-    return NULL;
+  DCHECK_GE(last_committed_entry_index_, 0);
+  DCHECK_LT(last_committed_entry_index_, GetEntryCount());
   return entries_[last_committed_entry_index_];
 }
 
@@ -792,8 +802,6 @@ bool NavigationControllerImpl::RendererDidNavigate(
     RenderFrameHostImpl* rfh,
     const FrameHostMsg_DidCommitProvisionalLoad_Params& params,
     LoadCommittedDetails* details) {
-  is_initial_navigation_ = false;
-
   // Save the previous state before we clobber it.
   if (GetLastCommittedEntry()) {
     details->previous_url = GetLastCommittedEntry()->GetURL();
@@ -827,6 +835,12 @@ bool NavigationControllerImpl::RendererDidNavigate(
                                  pending_entry_->should_replace_entry();
   }
 
+  // If this is the first navigation after the initial about:blank page, then it
+  // should replace the initial NavigationEntry, regardless of the checks above.
+  if (IsInitialBlankNavigation())
+    details->did_replace_entry = true;
+  is_initial_navigation_ = false;
+
   // Do navigation-type specific actions. These will make and commit an entry.
   details->type = ClassifyNavigation(rfh, params);
 
@@ -839,6 +853,9 @@ bool NavigationControllerImpl::RendererDidNavigate(
       RendererDidNavigateToNewPage(rfh, params, details->did_replace_entry);
       break;
     case NAVIGATION_TYPE_EXISTING_PAGE:
+      // TODO(creis): This is wrong.  See
+      // https://codereview.chromium.org/1214073005.  Shouldn't touch this value
+      // in most cases.
       details->did_replace_entry = details->is_in_page;
       RendererDidNavigateToExistingPage(rfh, params);
       break;
@@ -852,16 +869,6 @@ bool NavigationControllerImpl::RendererDidNavigate(
       if (!RendererDidNavigateAutoSubframe(rfh, params))
         return false;
       break;
-    case NAVIGATION_TYPE_NAV_IGNORE:
-      // If a pending navigation was in progress, this canceled it.  We should
-      // discard it and make sure it is removed from the URL bar.  After that,
-      // there is nothing we can do with this navigation, so we just return to
-      // the caller that nothing has happened.
-      if (pending_entry_) {
-        DiscardNonCommittedEntries();
-        delegate_->NotifyNavigationStateChanged(INVALIDATE_TYPE_URL);
-      }
-      return false;
     default:
       NOTREACHED();
   }
@@ -953,20 +960,9 @@ NavigationType NavigationControllerImpl::ClassifyNavigation(
   if (params.did_create_new_entry) {
     // A new entry. We may or may not have a pending entry for the page, and
     // this may or may not be the main frame.
-    if (!rfh->GetParent()) {
-      return NAVIGATION_TYPE_NEW_PAGE;
-    }
-
-    // When this is a new subframe navigation, we should have a committed page
-    // in which it's a subframe. This may not be the case when an iframe is
-    // navigated on a popup navigated to about:blank (the iframe would be
-    // written into the popup by script on the main page). For these cases,
-    // there isn't any navigation stuff we can do, so just ignore it.
-    if (!GetLastCommittedEntry())
-      return NAVIGATION_TYPE_NAV_IGNORE;
-
-    // Valid subframe navigation.
-    return NAVIGATION_TYPE_NEW_SUBFRAME;
+    return rfh->GetParent() ?
+        NAVIGATION_TYPE_NEW_SUBFRAME :
+        NAVIGATION_TYPE_NEW_PAGE;
   }
 
   // We only clear the session history when navigating to a new page.
@@ -975,28 +971,13 @@ NavigationType NavigationControllerImpl::ClassifyNavigation(
   if (rfh->GetParent()) {
     // All manual subframes would be did_create_new_entry and handled above, so
     // we know this is auto.
-    if (GetLastCommittedEntry()) {
-      return NAVIGATION_TYPE_AUTO_SUBFRAME;
-    } else {
-      // We ignore subframes created in non-committed pages; we'd appreciate if
-      // people stopped doing that.
-      return NAVIGATION_TYPE_NAV_IGNORE;
-    }
+    return NAVIGATION_TYPE_AUTO_SUBFRAME;
   }
 
   if (params.nav_entry_id == 0) {
     // This is a renderer-initiated navigation (nav_entry_id == 0), but didn't
-    // create a new page.
-
-    // Just like above in the did_create_new_entry case, it's possible to
-    // scribble onto an uncommitted page. Again, there isn't any navigation
-    // stuff that we can do, so ignore it here as well.
-    NavigationEntry* last_committed = GetLastCommittedEntry();
-    if (!last_committed)
-      return NAVIGATION_TYPE_NAV_IGNORE;
-
-    // This is history.replaceState(), history.reload(), or a client-side
-    // redirect.
+    // create a new page. This happens for history.replaceState(),
+    // history.reload(), or a client-side redirect.
     return NAVIGATION_TYPE_EXISTING_PAGE;
   }
 
@@ -1353,13 +1334,7 @@ bool NavigationControllerImpl::IsURLInPageNavigation(
   if (rfh->GetParent()) {
     last_committed_url = rfh->GetLastCommittedURL();
   } else {
-    NavigationEntry* last_committed = GetLastCommittedEntry();
-    // There must be a last-committed entry to compare URLs to. TODO(avi): When
-    // might Blink say that a navigation is in-page yet there be no last-
-    // committed entry?
-    if (!last_committed)
-      return false;
-    last_committed_url = last_committed->GetURL();
+    last_committed_url = GetLastCommittedEntry()->GetURL();
   }
 
   WebPreferences prefs = rfh->GetRenderViewHost()->GetWebkitPreferences();
@@ -1387,12 +1362,13 @@ void NavigationControllerImpl::CopyStateFrom(
   const NavigationControllerImpl& source =
       static_cast<const NavigationControllerImpl&>(temp);
   // Verify that we look new.
-  DCHECK(GetEntryCount() == 0 && !GetPendingEntry());
-
-  if (source.GetEntryCount() == 0)
-    return;  // Nothing new to do.
+  DCHECK(IsInitialBlankNavigation() && GetEntryCount() == 1 &&
+         !GetPendingEntry());
+  DCHECK_GT(source.GetEntryCount(), 0);
 
   needs_reload_ = true;
+  // Drop the initial entry first.
+  entries_.pop_back();
   InsertEntriesFrom(source, source.GetEntryCount());
 
   for (SessionStorageNamespaceMap::const_iterator it =
@@ -1469,7 +1445,7 @@ bool NavigationControllerImpl::CanPruneAllButLastCommitted() {
   // If there is no last committed entry, we cannot prune.  Even if there is a
   // pending entry, it may not commit, leaving this WebContents blank, despite
   // possibly giving it new entries via CopyStateFromAndPrune.
-  if (last_committed_entry_index_ == -1)
+  if (IsInitialBlankNavigation())
     return false;
 
   // We cannot prune if there is a pending entry at an existing entry index.
@@ -1537,9 +1513,28 @@ int32 NavigationControllerImpl::GetMaxRestoredPageID() const {
   return max_restored_page_id_;
 }
 
+void NavigationControllerImpl::Init(SiteInstance* instance) {
+  DCHECK(IsInitialNavigation());
+
+  // Start with an entry for the initial about:blank page, which will be
+  // replaced on first navigation.
+  scoped_ptr<NavigationEntryImpl> initial_entry =
+      make_scoped_ptr(new NavigationEntryImpl(
+          static_cast<SiteInstanceImpl*>(instance), -1,
+          GURL(url::kAboutBlankURL), Referrer(), base::string16(),
+          ui::PAGE_TRANSITION_LINK, false));
+
+  // Make sure the initial RenderFrameHost knows about it.
+  RenderFrameHostImpl* main_frame =
+      delegate_->GetFrameTree()->root()->current_frame_host();
+  static_cast<RenderViewHostImpl*>(main_frame->GetRenderViewHost())->
+      set_nav_entry_id(initial_entry->GetUniqueID());
+
+  entries_.push_back(initial_entry.Pass());
+}
+
 bool NavigationControllerImpl::IsUnmodifiedBlankTab() const {
-  return IsInitialNavigation() &&
-         !GetLastCommittedEntry() &&
+  return IsInitialBlankNavigation() &&
          !delegate_->HasAccessedInitialDocument();
 }
 
@@ -1987,8 +1982,7 @@ void NavigationControllerImpl::SetTransientEntry(
     scoped_ptr<NavigationEntry> entry) {
   // Discard any current transient entry, we can only have one at a time.
   int index = 0;
-  if (last_committed_entry_index_ != -1)
-    index = last_committed_entry_index_ + 1;
+  index = last_committed_entry_index_ + 1;
   DiscardTransientEntry();
   entries_.insert(entries_.begin() + index,
                   NavigationEntryImpl::FromNavigationEntry(entry.release()));