Move SessionStorageNamespace entirely into NavigationController and support StoragePartitions.

chrome/browser/instant/instant_loader.cc

Index: chrome/browser/instant/instant_loader.cc
diff --git a/chrome/browser/instant/instant_loader.cc b/chrome/browser/instant/instant_loader.cc
index 28dad8f8ddd82fd9bb6b52a1e07a65718b4fdc76..5ef65eabfdd6771b5c6168c983f96fa273f31291 100644
--- a/chrome/browser/instant/instant_loader.cc
+++ b/chrome/browser/instant/instant_loader.cc
@@ -93,7 +93,12 @@ void AddPreviewUsageForHistogram(TemplateURLID template_url_id,
 }
 
 SessionStorageNamespace* GetSessionStorageNamespace(TabContents* tab) {
-  return tab->web_contents()->GetController().GetSessionStorageNamespace();
+  // TODO(ajwong): This is wrong.  This whole chunk of code was going to be
+  // removed by:
+  //    http://codereview.chromium.org/10732002/
+  // but instead I will whack it in a followup CL.

[Charlie Reis, 2012/08/02 23:06:47]

Not sure we need to mention the obsolete CL.  Instead, just say a bit more on
why it's wrong and what you plan to do.  (Removing the default namespace?)

[sreeram, 2012/08/02 23:44:43]

That CL got rolled over into http://codereview.chromium.org/10836031/, so yes,
this code is still on track to be removed.

[awong, 2012/08/03 00:31:04]

Updated comment to refer to sreeram's new CL. Hopefully sreeram's CL gets
checked in first and then this will just go away-Away-AWAY!!! :D

+  return tab->web_contents()->GetController()
+      .GetSessionStorageNamespaceMap().find("")->second;
 }
 
 }  // namespace
@@ -850,6 +855,8 @@ TabContents* InstantLoader::ReleasePreviewContents(
       type == INSTANT_COMMIT_DESTROY ? PREVIEW_DELETED : PREVIEW_COMMITTED,
       group_);
   if (type != INSTANT_COMMIT_DESTROY) {
+    // This tracks the number of times a committed preview page destroys the
+    // Session Storage for the tab.
     base::Histogram* histogram = base::LinearHistogram::FactoryGet(
         "Instant.SessionStorageNamespace" + group_, 1, 2, 3,
         base::Histogram::kUmaTargetedHistogramFlag);
@@ -1143,7 +1150,7 @@ void InstantLoader::SetupPreviewContents(TabContents* tab_contents) {
 
 void InstantLoader::CreatePreviewContents(TabContents* tab_contents) {
   WebContents* new_contents = WebContents::Create(
-      tab_contents->profile(), NULL, MSG_ROUTING_NONE, NULL, NULL);
+      tab_contents->profile(), NULL, MSG_ROUTING_NONE, NULL);
   preview_contents_.reset(new TabContents(new_contents));
   AddPreviewUsageForHistogram(template_url_id_, PREVIEW_CREATED, group_);
   session_storage_namespace_ = GetSessionStorageNamespace(tab_contents);