Add SameSite level to ProactivelySwapBrowsingInstance

Adds the "SameSite" level to the ProactivelySwapBrowsingInstance feature
flag. This CL also adds helper functions (to parametrize tests, etc.).
The implementation for same-site proactive BI swap is done in another
CL - crrev.com/c/2121522.
Non-content uses of the functions: crrev.com/c/2210605,
crrev.com/c/2196105, and a few others.

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

Bug: 977562
Change-Id: I283ad31297ce6dd93bb6f02e8159488d62c5d989
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2214588Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Reviewed-by: Fergal Daly <fergal@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Commit-Queue: Rakina Zata Amni <rakina@chromium.org>
Cr-Commit-Position: refs/heads/master@{#774980}

content/common/content_navigation_policy.cc

@@ -47,7 +47,8 @@ constexpr base::FeatureParam<ProactivelySwapBrowsingInstanceLevel>::Option
         {ProactivelySwapBrowsingInstanceLevel::kCrossSiteSwapProcess,
          "CrossSiteSwapProcess"},
         {ProactivelySwapBrowsingInstanceLevel::kCrossSiteReuseProcess,
-         "CrossSiteReuseProcess"}};
+         "CrossSiteReuseProcess"},
+        {ProactivelySwapBrowsingInstanceLevel::kSameSite, "SameSite"}};
 const base::FeatureParam<ProactivelySwapBrowsingInstanceLevel>
     proactively_swap_browsing_instance_level{
         &features::kProactivelySwapBrowsingInstance,
@@ -55,6 +56,24 @@ const base::FeatureParam<ProactivelySwapBrowsingInstanceLevel>
         ProactivelySwapBrowsingInstanceLevel::kDisabled,
         &proactively_swap_browsing_instance_levels};
 
+std::string GetProactivelySwapBrowsingInstanceLevelName(
+    ProactivelySwapBrowsingInstanceLevel level) {
+  return proactively_swap_browsing_instance_level.GetName(level);
+}
+
+std::array<std::string,
+           static_cast<size_t>(ProactivelySwapBrowsingInstanceLevel::kMaxValue)>
+ProactivelySwapBrowsingInstanceFeatureEnabledLevelValues() {
+  return {
+      GetProactivelySwapBrowsingInstanceLevelName(
+          ProactivelySwapBrowsingInstanceLevel::kCrossSiteSwapProcess),
+      GetProactivelySwapBrowsingInstanceLevelName(
+          ProactivelySwapBrowsingInstanceLevel::kCrossSiteReuseProcess),
+      GetProactivelySwapBrowsingInstanceLevelName(
+          ProactivelySwapBrowsingInstanceLevel::kSameSite),
+  };
+}
+
 ProactivelySwapBrowsingInstanceLevel GetProactivelySwapBrowsingInstanceLevel() {
   if (base::FeatureList::IsEnabled(features::kProactivelySwapBrowsingInstance))
     return proactively_swap_browsing_instance_level.Get();
@@ -70,6 +89,12 @@ bool IsProactivelySwapBrowsingInstanceWithProcessReuseEnabled() {
   return GetProactivelySwapBrowsingInstanceLevel() >=
          ProactivelySwapBrowsingInstanceLevel::kCrossSiteReuseProcess;
 }
+
+bool IsProactivelySwapBrowsingInstanceOnSameSiteNavigationEnabled() {
+  return GetProactivelySwapBrowsingInstanceLevel() >=
+         ProactivelySwapBrowsingInstanceLevel::kSameSite;
+}
+
 const char kRenderDocumentLevelParameterName[] = "level";
 
 constexpr base::FeatureParam<RenderDocumentLevel>::Option

content/common/content_navigation_policy.h

@@ -24,12 +24,33 @@ enum class ProactivelySwapBrowsingInstanceLevel {
   // Swap BrowsingInstance on cross-site navigations, but try to reuse the
   // current renderer process if possible.
   kCrossSiteReuseProcess = 2,
-  // TODO(rakina): Add another level for BrowsingInstance swap on same-site
-  // navigations with process reuse.
+  // Swap BrowsingInstance swap on same-site navigations, with process reuse.
+  kSameSite = 3,
+
+  kMaxValue = kSameSite,
 };
+
+// Levels of ProactivelySwapBrowsingInstance as strings (excluding kDisabled).
+CONTENT_EXPORT std::array<
+    std::string,
+    static_cast<size_t>(ProactivelySwapBrowsingInstanceLevel::kMaxValue)>
+ProactivelySwapBrowsingInstanceFeatureEnabledLevelValues();
+
+// Whether ProactivelySwapBrowsingInstance is enabled or not. Will return true
+// if the value is set to either of {kCrossSiteSwapProcess,
+// kCrossSiteReuseProcess, kSameSite}.
 CONTENT_EXPORT bool IsProactivelySwapBrowsingInstanceEnabled();
 
+// Whether ProactivelySwapBrowsingInstance with process reuse is enabled or not.
+// Will return true if the value is set to either of {kCrossSiteReuseProcess,
+// kSameSite}.
 CONTENT_EXPORT bool IsProactivelySwapBrowsingInstanceWithProcessReuseEnabled();
+
+// Whether ProactivelySwapBrowsingInstance for same-site navigation is enabled
+// or not. Will return true if the value is set to kSameSite.
+CONTENT_EXPORT bool
+IsProactivelySwapBrowsingInstanceOnSameSiteNavigationEnabled();
+
 CONTENT_EXPORT extern const char
     kProactivelySwapBrowsingInstanceLevelParameterName[];
 

content/public/test/test_utils.cc

@@ -24,6 +24,7 @@
 #include "build/build_config.h"
 #include "content/browser/frame_host/render_frame_host_delegate.h"
 #include "content/browser/frame_host/render_frame_host_impl.h"
+#include "content/common/content_navigation_policy.h"
 #include "content/public/browser/browser_child_process_host_iterator.h"
 #include "content/public/browser/browser_plugin_guest_delegate.h"
 #include "content/public/browser/browser_task_traits.h"
@@ -209,6 +210,12 @@ void IsolateAllSitesForTesting(base::CommandLine* command_line) {
   command_line->AppendSwitch(switches::kSitePerProcess);
 }
 
+bool CanSameSiteMainFrameNavigationsChangeRenderFrameHosts() {
+  // TODO(crbug.com/936696): Also return true when RenderDocument for main frame
+  // is enabled.
+  return IsProactivelySwapBrowsingInstanceOnSameSiteNavigationEnabled();
+}
+
 GURL GetWebUIURL(const std::string& host) {
   return GURL(GetWebUIURLString(host));
 }

content/public/test/test_utils.h

@@ -100,6 +100,11 @@ bool AreDefaultSiteInstancesEnabled();
 // the test; the flag will be read on the first real navigation.
 void IsolateAllSitesForTesting(base::CommandLine* command_line);
 
+// Whether same-site navigations might result in a change of RenderFrameHosts -
+// this will happen when ProactivelySwapBrowsingInstance or RenderDocument
+// is enabled on same-site main frame navigations.
+bool CanSameSiteMainFrameNavigationsChangeRenderFrameHosts();
+
 // Returns a GURL constructed from the WebUI scheme and the given host.
 GURL GetWebUIURL(const std::string& host);