Don't split off NTP subframes with TDI.

chrome/browser/chrome_content_browser_client.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chrome_content_browser_client.h"
 
 #include <map>
 #include <set>
 #include <utility>
 #include <vector>
@@ skipping 1199 matching lines @@
       url.SchemeIs(content::kChromeUIScheme) &&
       url.host_piece() != chrome::kChromeUIChromeSigninHost) {
     VLOG(1) << "Blocked navigation to " << url.spec() << " from "
             << chrome::kChromeUIChromeSigninURL;
     return false;
   }
 
   return true;
 }
 
+namespace {
+
+// Returns whether a SiteInstance holds a NTP. TODO(mastiz): This
+// really really really needs to be moved to a shared place where all the code
+// that needs to know this can access it. See http://crbug.com/624410.
+bool IsNTPSiteInstance(SiteInstance* site_instance) {
+  // While using SiteInstance::GetSiteURL() is unreliable and the wrong thing to
+  // use for making security decisions 99.44% of the time, for detecting the NTP
+  // it is reliable and the correct way. Again, see http://crbug.com/624410.
+  return site_instance &&
+         site_instance->GetSiteURL().SchemeIs(chrome::kChromeSearchScheme) &&
+         (site_instance->GetSiteURL().host_piece() ==
+              chrome::kChromeSearchRemoteNtpHost ||
+          site_instance->GetSiteURL().host_piece() ==
+              chrome::kChromeSearchLocalNtpHost);
+}
+
+}  // namespace
+
 void ChromeContentBrowserClient::OverrideNavigationParams(
     SiteInstance* site_instance,
     ui::PageTransition* transition,
     bool* is_renderer_initiated,
     content::Referrer* referrer) {
   DCHECK(transition);
   DCHECK(is_renderer_initiated);
   DCHECK(referrer);
   // TODO(crbug.com/624410): Factor the predicate to identify a URL as an NTP
   // to a shared library.
-  if (site_instance &&
-      site_instance->GetSiteURL().SchemeIs(chrome::kChromeSearchScheme) &&
-      (site_instance->GetSiteURL().host_piece() ==
-           chrome::kChromeSearchRemoteNtpHost ||
-       site_instance->GetSiteURL().host_piece() ==
-           chrome::kChromeSearchLocalNtpHost) &&
+  if (IsNTPSiteInstance(site_instance) &&
       ui::PageTransitionCoreTypeIs(*transition, ui::PAGE_TRANSITION_LINK)) {
     // Use AUTO_BOOKMARK for clicks on tiles of the new tab page, consistently
     // with native implementations like Android's.
     *transition = ui::PAGE_TRANSITION_AUTO_BOOKMARK;
     *is_renderer_initiated = false;
     *referrer = content::Referrer();
   }
 
 #if BUILDFLAG(ENABLE_EXTENSIONS)
   ChromeContentBrowserClientExtensionsPart::OverrideNavigationParams(
       site_instance, transition, is_renderer_initiated, referrer);
 #endif
 }
 
+bool ChromeContentBrowserClient::
+    ShouldFrameShareParentSiteInstanceDespiteTopDocumentIsolation(
+        const GURL& url,
+        content::SiteInstance* parent_site_instance) {
+  return IsNTPSiteInstance(parent_site_instance);
+}
+
 bool ChromeContentBrowserClient::IsSuitableHost(
     content::RenderProcessHost* process_host,
     const GURL& site_url) {
   Profile* profile =
       Profile::FromBrowserContext(process_host->GetBrowserContext());
   // This may be NULL during tests. In that case, just assume any site can
   // share any host.
   if (!profile)
     return true;
 
@@ skipping 1979 matching lines @@
                                       kWebRtcDevSwitchNames,
                                       arraysize(kWebRtcDevSwitchNames));
   }
 }
 #endif  // defined(ENABLE_WEBRTC)
 
 std::unique_ptr<content::MemoryCoordinatorDelegate>
 ChromeContentBrowserClient::GetMemoryCoordinatorDelegate() {
   return memory::ChromeMemoryCoordinatorDelegate::Create();
 }