Lazily load extension API schemas

chrome/common/extensions/features/permission_feature.cc

Index: chrome/common/extensions/features/permission_feature.cc
diff --git a/chrome/common/extensions/features/permission_feature.cc b/chrome/common/extensions/features/permission_feature.cc
index b6085d22b122464faea00e1cb1715286d29ee01e..572fc5bf2695129de09e0f4e9c6e91301a78ab81 100644
--- a/chrome/common/extensions/features/permission_feature.cc
+++ b/chrome/common/extensions/features/permission_feature.cc
@@ -4,6 +4,8 @@
 
 #include "chrome/common/extensions/features/permission_feature.h"
 
+#include "chrome/common/extensions/permissions/permission_set.h"
+
 namespace extensions {
 
 PermissionFeature::PermissionFeature() {
@@ -15,15 +17,19 @@ PermissionFeature::~PermissionFeature() {
 Feature::Availability PermissionFeature::IsAvailableToContext(
     const Extension* extension,
     Feature::Context context,
+    const GURL& url,
     Feature::Platform platform) const {
   Availability availability = SimpleFeature::IsAvailableToContext(extension,
                                                                   context,
+                                                                  url,
                                                                   platform);
   if (!availability.is_available())
     return availability;
 
-  if (!extension->HasAPIPermission(name()))
+  if (extension && !extension->HasAPIPermission(name()) &&
+      !extension->optional_permission_set()->HasAnyAccessToAPI(name())) {

[not at google - send to devlin, 2013/03/22 23:04:30]

could you explain this in a comment?

     return CreateAvailability(NOT_PRESENT, extension->GetType());
+  }
 
   return CreateAvailability(IS_AVAILABLE);
 }