Revert "Reland "[SessionStorageS13N] Enabling mojo SessionStorage by default""

This reverts commit bbe0692bd9283569546670318df6e3d8e605be8c.

Reason for revert: We actually want this change reverted :). The original CL was bad, the revert was a manual thing done by the sheriff. The GoB fix then re-landed this, and now we want to reland it again.

Original change's description:
> Reland "[SessionStorageS13N] Enabling mojo SessionStorage by default"
> 
> This reverts commit 304663b467d33fbe0a7e552565aceb5a59d8b2b0.
> 
> Reason for revert: Due to Gerrit outage http://crbug.com/872722, we are reverting this CL. Please, re-land it after all clear is given. If you have questions, please ask on the bug. Sorry for the inconvenience.
> 
> Original change's description:
> > Revert "[SessionStorageS13N] Enabling mojo SessionStorage by default"
> > 
> > This reverts commit 1bd58466.
> > 
> > Reason for revert: The crashes are still happening, and we aren't
> >                    closer to finding the cause. Changing focus to the
> >                    onion-souping effort.
> > 
> > Bug: 859464, 857464, 867850, 866827
> > 
> > Original change's description:
> > > [SessionStorageS13N] Enabling mojo SessionStorage by default
> > > 
> > > Bug: 716490
> > > Change-Id: I08c9bc35d1e9f8f86adc6c88fb7ab8069bcf7e8f
> > > Reviewed-on: https://chromium-review.googlesource.com/1072918
> > > Reviewed-by: Marijn Kruisselbrink <mek@chromium.org>
> > > Reviewed-by: John Abd-El-Malek <jam@chromium.org>
> > > Commit-Queue: Daniel Murphy <dmurph@chromium.org>
> > > Cr-Commit-Position: refs/heads/master@{#563169}
> > 
> > TBR=dmurph@chromium.org,jam@chromium.org,mek@chromium.org
> > 
> > # Not skipping CQ checks because original CL landed > 1 day ago.
> > 
> > Bug: 716490
> > Change-Id: Ic5223ccbff4d61264c070b3518cf63ddb83deeb0
> > Reviewed-on: https://chromium-review.googlesource.com/1157446
> > Reviewed-by: Daniel Murphy <dmurph@chromium.org>
> 
> TBR=dmurph@chromium.org,jam@chromium.org,mek@chromium.org
> 
> Change-Id: Ia063033d68cd05bc46ca9259ed9f49e5ee06bab9
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: 859464, 857464, 867850, 866827, 716490
> Reviewed-on: https://chromium-review.googlesource.com/1169843
> Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>

TBR=dmurph@chromium.org,jam@chromium.org,mek@chromium.org,tandrii@chromium.org

Change-Id: I3ff96a37dd11d2986651dbd8a7156178c20fb018
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 859464, 857464, 867850, 866827, 716490
Reviewed-on: https://chromium-review.googlesource.com/1170005Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Dirk Pranke <dpranke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#581909}

chrome/browser/browsing_data/browsing_data_remover_browsertest.cc

@@ -240,15 +240,16 @@ std::string GetCookiesTreeModelInfo(const CookieTreeNode* root) {
 
 class BrowsingDataRemoverBrowserTest : public InProcessBrowserTest {
  public:
-  BrowsingDataRemoverBrowserTest() {}
-
-  void SetUpOnMainThread() override {
+  BrowsingDataRemoverBrowserTest() {
     feature_list_.InitWithFeatures(
         {browsing_data::features::kRemoveNavigationHistory,
          // Ensure that MojoSessionStorage is enabled because the old
          // SessionStorage implementation causes flaky tests.
          features::kMojoSessionStorage},
         {});
+  }
+
+  void SetUpOnMainThread() override {
     base::FilePath path;
     base::PathService::Get(content::DIR_TEST_DATA, &path);
     host_resolver()->AddRule(kExampleHost, "127.0.0.1");

content/public/common/content_features.cc

@@ -255,7 +255,7 @@ const base::Feature kModuleScriptsImportMetaUrl{
 
 // Mojo-based Session Storage.
 const base::Feature kMojoSessionStorage{"MojoSessionStorage",
-                                        base::FEATURE_ENABLED_BY_DEFAULT};
+                                        base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Enables/disables the video capture service.
 const base::Feature kMojoVideoCapture {