PlzNavigate: AppCache support.

content/browser/appcache/appcache_backend_impl.cc

Index: content/browser/appcache/appcache_backend_impl.cc
diff --git a/content/browser/appcache/appcache_backend_impl.cc b/content/browser/appcache/appcache_backend_impl.cc
index 7f29c3e97a713cb7a13924b6cc27a7fb9113627a..6b98b02c3761b4d3941253ba0baf8e77b08a20e5 100644
--- a/content/browser/appcache/appcache_backend_impl.cc
+++ b/content/browser/appcache/appcache_backend_impl.cc
@@ -8,6 +8,8 @@
 #include "content/browser/appcache/appcache.h"
 #include "content/browser/appcache/appcache_group.h"
 #include "content/browser/appcache/appcache_service_impl.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/common/browser_side_navigation_policy.h"
 
 namespace content {
 
@@ -34,8 +36,22 @@ void AppCacheBackendImpl::Initialize(AppCacheServiceImpl* service,
 }
 
 bool AppCacheBackendImpl::RegisterHost(int id) {
-  if (GetHost(id))
+  AppCacheHost* host = GetHost(id);
+
+  if (host) {
+    // PlzNavigate. The is precreated which means we want to avoid registering
+    // it again.
+    if (IsBrowserSideNavigationEnabled()) {
+      auto found = pending_hosts_.find(id);
+      DCHECK(found != pending_hosts_.end());

[michaeln, 2016/12/05 21:52:54]

Since this |id| is given to us by a potentially compromised renderer, if its not
found in pending_host_, it might be better to return false, which indicates a
badipc and will cause the renderer to be killed.
(this comment might not apply depending... see the other comment)

[ananta, 2016/12/06 01:24:38]

The pending hosts are no longer needed with your suggestion about the service
worker pattern.

+      pending_hosts_.erase(found);
+      // Switch the frontend proxy so that the host can make IPC calls from
+      // here on.
+      host->set_frontend(frontend_);
+      return true;
+    }
     return false;
+  }
 
   hosts_[id] = base::MakeUnique<AppCacheHost>(id, frontend_, service_);
   return true;
@@ -166,4 +182,19 @@ void AppCacheBackendImpl::TransferHostIn(int new_host_id,
   found->second = std::move(host);
 }
 
+void AppCacheBackendImpl::RegisterPrecreatedHost(
+    std::unique_ptr<AppCacheHost> host) {
+  DCHECK(IsBrowserSideNavigationEnabled());
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  DCHECK(host.get());
+  // Mark the host as pending so we can avoid registering it again in the
+  // RegisterHost() call.
+  DCHECK(pending_hosts_.find(host->host_id()) == pending_hosts_.end());
+  pending_hosts_.insert(host->host_id());
+
+  DCHECK(hosts_.find(host->host_id()) == hosts_.end());
+  hosts_[host->host_id()] = std::move(host);
+}
+
 }  // namespace content