Same-site Proactive BrowsingInstance Swap

This CL adds the capability of doing proactive BrowsingInstance swap on
same-site main-frame navigations when the "SameSite" level is set on the
"ProactivelySwapBrowsingInstance" flag. With that, some main-frame
same-site navigations will result in a new BrowsingInstance,
SiteInstance, RenderFrameHost, RenderView, etc.

This CL does not include:
- Updates for tests that fails because they didn't expect a change of
RenderFrameHosts, etc. on same-site main frame navigations. These are
handled in other CLs.
- Fix to ensure order of unload handlers on same-site cross-RFH
navigations (will be fixed on a future CL)
- Fix to ensure WebPreferences are carried over for cross-RFH same-site
navigations (will be fixed on a future CL)

For more details, see doc: https://docs.google.com/document/d/1lHdkKLUe8H6ZP6ALwj-dsus7oYcuc93HkSCHCcerItg/edit?usp=sharing

Bug: 977562
Change-Id: I455e598d1c422984cb707bb3a8b54fa926bb5911
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2121522
Commit-Queue: Rakina Zata Amni <rakina@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#779712}

content/browser/frame_host/render_frame_host_manager.h

@@ -606,12 +606,15 @@ class CONTENT_EXPORT RenderFrameHostManager
       ui::PageTransition transition,
       bool is_failure,
       bool is_reload,
+      bool is_same_document,
       bool cross_origin_opener_policy_mismatch,
-      bool was_server_redirect);
+      bool was_server_redirect,
+      bool should_replace_current_entry);
 
   ShouldSwapBrowsingInstance ShouldProactivelySwapBrowsingInstance(
-      RenderFrameHostImpl* current_rfh,
-      const GURL& destination_url);
+      const GURL& destination_url,
+      bool is_reload,
+      bool should_replace_current_entry);
 
   // Returns the SiteInstance to use for the navigation.
   scoped_refptr<SiteInstance> GetSiteInstanceForNavigation(
@@ -622,10 +625,12 @@ class CONTENT_EXPORT RenderFrameHostManager
       ui::PageTransition transition,
       bool is_failure,
       bool is_reload,
+      bool is_same_document,
       bool dest_is_restore,
       bool dest_is_view_source_mode,
       bool was_server_redirect,
-      bool cross_origin_opener_policy_mismatch);
+      bool cross_origin_opener_policy_mismatch,
+      bool should_replace_current_entry);
 
   // Returns a descriptor of the appropriate SiteInstance object for the given
   // |dest_url|, possibly reusing the current, source or destination

content/browser/frame_host/should_swap_browsing_instance.h

@@ -24,9 +24,15 @@ enum class ShouldSwapBrowsingInstance {
   kNo_AlreadyHasMatchingBrowsingInstance = 9,
   kNo_RendererDebugURL = 10,
   kNo_NotNeededForBackForwardCache = 11,
-  kYes_ProactiveSwap = 12,
+  kYes_CrossSiteProactiveSwap = 12,
+  kYes_SameSiteProactiveSwap = 13,
+  kNo_SameDocumentNavigation = 14,
+  kNo_SamePageNavigation = 15,
+  kNo_WillReplaceEntry = 16,
+  kNo_Reload = 17,
+  kNo_Guest = 18,
 
-  kMaxValue = kYes_ProactiveSwap
+  kMaxValue = kNo_Guest
 };
 
 }  // namespace content

content/browser/site_instance_impl.cc

@@ -326,8 +326,10 @@ RenderProcessHost* SiteInstanceImpl::GetProcess() {
 
 void SiteInstanceImpl::ReuseCurrentProcessIfPossible(
     RenderProcessHost* current_process) {
-  if (IsGuest() || HasProcess() || RequiresDedicatedProcess())
+  DCHECK(!IsGuest());
+  if (HasProcess())
     return;
+
   // We should not reuse the current process if the destination uses
   // process-per-site. Note that this includes the case where the process for
   // the site is not there yet (so we're going to create a new process).
@@ -335,13 +337,19 @@ void SiteInstanceImpl::ReuseCurrentProcessIfPossible(
   // process is used for a process-per-site site, it is ok to reuse this for the
   // new page (regardless of the site).
   if (HasSite() && RenderProcessHostImpl::ShouldUseProcessPerSite(
-                       browsing_instance_->GetBrowserContext(), site_))
+                       browsing_instance_->GetBrowserContext(), site_)) {
     return;
+  }
+
+  // Do not reuse the process if it's not suitable for this SiteInstance. For
+  // example, this won't allow reusing a process if it's locked to a site that's
+  // different from this SiteInstance's site.
   if (!current_process->MayReuseHost() ||
       !RenderProcessHostImpl::IsSuitableHost(
           current_process, GetIsolationContext(), site_.site_url(), lock_url(),
-          IsGuest()))
+          IsGuest())) {
     return;
+  }
   SetProcessInternal(current_process);
 }
 

content/public/test/content_browser_test_utils.cc

@@ -94,12 +94,18 @@ bool NavigateToURL(Shell* window,
 
 bool NavigateToURLFromRenderer(const ToRenderFrameHost& adapter,
                                const GURL& url) {
+  return NavigateToURLFromRenderer(adapter, url, url);
+}
+
+bool NavigateToURLFromRenderer(const ToRenderFrameHost& adapter,
+                               const GURL& url,
+                               const GURL& expected_commit_url) {
   RenderFrameHost* rfh = adapter.render_frame_host();
   TestFrameNavigationObserver nav_observer(rfh);
   if (!ExecJs(rfh, JsReplace("location = $1", url)))
     return false;
   nav_observer.Wait();
-  return nav_observer.last_committed_url() == url &&
+  return nav_observer.last_committed_url() == expected_commit_url &&
          nav_observer.last_navigation_succeeded();
 }
 

content/public/test/content_browser_test_utils.h

@@ -93,6 +93,13 @@ WARN_UNUSED_RESULT bool NavigateToURL(Shell* window,
 WARN_UNUSED_RESULT bool NavigateToURLFromRenderer(
     const ToRenderFrameHost& adapter,
     const GURL& url);
+// Similar to above but takes in an additional URL, |expected_commit_url|, to
+// which the navigation should eventually commit. (See the browser-initiated
+// counterpart for more details).
+WARN_UNUSED_RESULT bool NavigateToURLFromRenderer(
+    const ToRenderFrameHost& adapter,
+    const GURL& url,
+    const GURL& expected_commit_url);
 WARN_UNUSED_RESULT bool NavigateToURLFromRendererWithoutUserGesture(
     const ToRenderFrameHost& adapter,
     const GURL& url);