Allow shared modules to whitelist extensions that import them.

extensions/common/manifest_handlers/shared_module_info.cc

Index: extensions/common/manifest_handlers/shared_module_info.cc
diff --git a/extensions/common/manifest_handlers/shared_module_info.cc b/extensions/common/manifest_handlers/shared_module_info.cc
index 5f4416099271c38d4565c835eb2f68b9cbe65af0..ac95ee5b07440270e2afb9bb64272c2981473597 100644
--- a/extensions/common/manifest_handlers/shared_module_info.cc
+++ b/extensions/common/manifest_handlers/shared_module_info.cc
@@ -84,6 +84,17 @@ bool SharedModuleInfo::IsExportAllowed(const Extension* extension,
 }
 
 // static
+bool SharedModuleInfo::IsExportAllowedByWhitelist(const Extension* extension,
+                                                  const std::string& other_id) {
+  const SharedModuleInfo& info = GetSharedModuleInfo(extension);
+  if (info.export_whitelist_.empty())
+    return true;
+  if (info.export_whitelist_.find(other_id) != info.export_whitelist_.end())
+    return true;
+  return false;
+}
+
+// static
 bool SharedModuleInfo::ImportsExtensionById(const Extension* extension,
                                             const std::string& other_id) {
   const SharedModuleInfo& info = GetSharedModuleInfo(extension);
@@ -128,6 +139,23 @@ bool SharedModuleInfo::Parse(const Extension* extension,
       *error = base::ASCIIToUTF16(errors::kInvalidExportResources);
       return false;
     }
+    if (export_value->HasKey(keys::kWhitelist)) {
+      const base::ListValue* whitelist = NULL;
+      if (!export_value->GetList(keys::kWhitelist, &whitelist)) {
+        *error = base::ASCIIToUTF16(errors::kInvalidExportWhitelist);
+        return false;
+      }
+      for (size_t i = 0; i < whitelist->GetSize(); ++i) {
+        std::string extension_id;
+        if (!whitelist->GetString(i, &extension_id) ||
+            !Extension::IdIsValid(extension_id)) {
+          *error = ErrorUtils::FormatErrorMessageUTF16(
+              errors::kInvalidExportWhitelistString, base::IntToString(i));
+          return false;
+        }
+        export_whitelist_.insert(extension_id);
+      }
+    }
     for (size_t i = 0; i < resources_list->GetSize(); ++i) {
       std::string resource_path;
       if (!resources_list->GetString(i, &resource_path)) {