PlzNavigate: ensure we don't create extra-processes for ServiceWorkers

content/browser/browsing_instance.cc

Index: content/browser/browsing_instance.cc
diff --git a/content/browser/browsing_instance.cc b/content/browser/browsing_instance.cc
index 5dd0ca4191fe832c5d4eea078c9cab946a8d397b..5705dcecd806b3d731c03bfccc38ee4fb37fa96b 100644
--- a/content/browser/browsing_instance.cc
+++ b/content/browser/browsing_instance.cc
@@ -15,16 +15,49 @@
 
 namespace content {
 
+namespace {
+
+using BrowsingInstanceList = std::set<BrowsingInstance*>;
+base::LazyInstance<BrowsingInstanceList>::DestructorAtExit
+    g_browsing_instance_list = LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+// static
+scoped_refptr<SiteInstanceImpl> BrowsingInstance::FindSiteInstance(
+    BrowserContext* browser_context,
+    const GURL& url) {
+  for (BrowsingInstance* browsing_instance : g_browsing_instance_list.Get()) {
+    if (browsing_instance->browser_context() == browser_context &&
+        browsing_instance->HasSiteInstance(url)) {
+      return browsing_instance->GetSiteInstanceForURL(url);
+    }
+  }
+  std::string site = SiteInstanceImpl::GetSiteForURL(browser_context, url)
+                         .possibly_invalid_spec();
+  for (BrowsingInstance* browsing_instance : g_browsing_instance_list.Get()) {
+    if (browsing_instance->browser_context() != browser_context)
+      continue;
+    if (browsing_instance->site_to_site_instance_map_.find(site) !=
+        browsing_instance->site_to_site_instance_map_.end()) {
+      for (SiteInstanceImpl* instance :
+           browsing_instance->site_to_site_instance_map_[site]) {
+        return instance;
+      }
+    }
+  }
+  return nullptr;
+}
+
 BrowsingInstance::BrowsingInstance(BrowserContext* browser_context)
-    : browser_context_(browser_context),
-      active_contents_count_(0u) {
+    : browser_context_(browser_context), active_contents_count_(0u) {
+  g_browsing_instance_list.Get().insert(this);
 }
 
 bool BrowsingInstance::HasSiteInstance(const GURL& url) {
   std::string site =
       SiteInstanceImpl::GetSiteForURL(browser_context_, url)
           .possibly_invalid_spec();
-
   return site_instance_map_.find(site) != site_instance_map_.end();
 }
 
@@ -102,7 +135,28 @@ void BrowsingInstance::UnregisterSiteInstance(SiteInstanceImpl* site_instance) {
     default_subframe_site_instance_ = nullptr;
 }
 
+void BrowsingInstance::RegisterUsedFor(SiteInstanceImpl* site_instance,
+                                       std::string site) {
+  auto instances = site_to_site_instance_map_.find(site);
+  if (instances == site_to_site_instance_map_.end())
+    site_to_site_instance_map_[site] = std::set<SiteInstanceImpl*>();
+  site_to_site_instance_map_[site].insert(site_instance);
+}
+
+void BrowsingInstance::UnregisterUsedFor(SiteInstanceImpl* site_instance,
+                                         const std::set<std::string>& sites) {
+  for (const auto& site : sites) {
+    if (site_to_site_instance_map_.find(site) !=
+        site_to_site_instance_map_.end()) {
+      site_to_site_instance_map_[site].erase(site_instance);
+      if (site_to_site_instance_map_[site].empty())
+        site_to_site_instance_map_.erase(site);
+    }
+  }
+}
+
 BrowsingInstance::~BrowsingInstance() {
+  g_browsing_instance_list.Get().erase(this);
   // We should only be deleted when all of the SiteInstances that refer to
   // us are gone.
   DCHECK(site_instance_map_.empty());