Fix the origin access whitelist for extensions

extensions/renderer/dispatcher.cc

Index: extensions/renderer/dispatcher.cc
diff --git a/extensions/renderer/dispatcher.cc b/extensions/renderer/dispatcher.cc
index fa242177fa2341141849ce945ff916f1a5f9a356..5a2a481f2bc78d142be9b840549801e682100817 100644
--- a/extensions/renderer/dispatcher.cc
+++ b/extensions/renderer/dispatcher.cc
@@ -271,7 +271,7 @@ void Dispatcher::DidCreateScriptContext(
   // Initialize origin permissions for content scripts, which can't be
   // initialized in |OnActivateExtension|.
   if (context_type == Feature::CONTENT_SCRIPT_CONTEXT)
-    UpdateOriginPermissions(extension);
+    InitOriginPermissions(extension);
 
   {
     scoped_ptr<ModuleSystem> module_system(
@@ -506,7 +506,7 @@ void Dispatcher::WebKitInitialized() {
     const Extension* extension = extensions_.GetByID(*iter);
     CHECK(extension);
 
-    UpdateOriginPermissions(extension);
+    InitOriginPermissions(extension);
   }
 
   EnableCustomElementWhiteList();
@@ -565,7 +565,7 @@ void Dispatcher::OnActivateExtension(const std::string& extension_id) {
     extensions::DOMActivityLogger::AttachToWorld(
         extensions::DOMActivityLogger::kMainWorldId, extension_id);
 
-    UpdateOriginPermissions(extension);
+    InitOriginPermissions(extension);
   }
 
   UpdateActiveExtensions();
@@ -741,8 +741,14 @@ void Dispatcher::OnUpdatePermissions(
   scoped_refptr<const PermissionSet> withheld =
       params.withheld_permissions.ToPermissionSet();
 
+  if (is_webkit_initialized_) {
+    UpdateOriginPermissions(
+        extension,
+        active->effective_hosts(),
+        extension->permissions_data()->GetEffectiveHostPermissions());
+  }
+
   extension->permissions_data()->SetPermissions(active, withheld);
-  UpdateOriginPermissions(extension);
   UpdateBindings(extension->id());
 }
 
@@ -771,28 +777,50 @@ void Dispatcher::UpdateActiveExtensions() {
   delegate_->OnActiveExtensionsUpdated(active_extensions);
 }
 
-void Dispatcher::UpdateOriginPermissions(const Extension* extension) {
-  const URLPatternSet& hosts =
-      extension->permissions_data()->GetEffectiveHostPermissions();
-  WebSecurityPolicy::resetOriginAccessWhitelists();
+void Dispatcher::InitOriginPermissions(const Extension* extension) {
   delegate_->InitOriginPermissions(extension,
                                    IsExtensionActive(extension->id()));
-  for (URLPatternSet::const_iterator iter = hosts.begin(); iter != hosts.end();
-       ++iter) {
-    const char* schemes[] = {
-        url::kHttpScheme,
-        url::kHttpsScheme,
-        url::kFileScheme,
-        content::kChromeUIScheme,
-        url::kFtpScheme,
-    };
-    for (size_t j = 0; j < arraysize(schemes); ++j) {
-      if (iter->MatchesScheme(schemes[j])) {
+  UpdateOriginPermissions(
+      extension,
+      extension->permissions_data()->GetEffectiveHostPermissions(),
+      URLPatternSet());  // No old permissions.
+}
+
+void Dispatcher::UpdateOriginPermissions(
+    const Extension* extension,
+    const URLPatternSet& new_patterns,

[not at google - send to devlin, 2014/07/23 17:01:17]

nit: could you swap new_patterns and old_patterns? this order (new then old) is
opposite to what I expect.

[Devlin, 2014/07/23 17:20:58]

Done.

+    const URLPatternSet& old_patterns) {
+  static const char* kSchemes[] = {
+      url::kHttpScheme,
+      url::kHttpsScheme,
+      url::kFileScheme,
+      content::kChromeUIScheme,
+      url::kFtpScheme,
+  };
+  for (size_t i = 0; i < arraysize(kSchemes); ++i) {
+    const char* scheme = kSchemes[i];
+    // Remove all old patterns that aren't also in the new patterns.
+    for (URLPatternSet::const_iterator pattern = old_patterns.begin();
+         pattern != old_patterns.end(); ++pattern) {
+      if (pattern->MatchesScheme(scheme) &&
+          !new_patterns.ContainsPattern(*pattern)) {
+        WebSecurityPolicy::removeOriginAccessWhitelistEntry(
+            extension->url(),
+            WebString::fromUTF8(scheme),
+            WebString::fromUTF8(pattern->host()),
+            pattern->match_subdomains());
+      }
+    }
+    for (URLPatternSet::const_iterator pattern = new_patterns.begin();
+         pattern != new_patterns.end(); ++pattern) {
+      // Add any new patterns that weren't in the old patterns.

[not at google - send to devlin, 2014/07/23 17:01:17]

nit: this comment should be up a couple of lines to match the placement of the
other one

[Devlin, 2014/07/23 17:20:58]

Done.

+      if (pattern->MatchesScheme(scheme) &&
+          !old_patterns.ContainsPattern(*pattern)) {
         WebSecurityPolicy::addOriginAccessWhitelistEntry(
             extension->url(),
-            WebString::fromUTF8(schemes[j]),
-            WebString::fromUTF8(iter->host()),
-            iter->match_subdomains());
+            WebString::fromUTF8(scheme),
+            WebString::fromUTF8(pattern->host()),
+            pattern->match_subdomains());
       }
     }
   }