Allow shared modules to whitelist extensions that import them.

extensions/common/manifest_constants.cc

Index: extensions/common/manifest_constants.cc
diff --git a/extensions/common/manifest_constants.cc b/extensions/common/manifest_constants.cc
index e0433b3b00e6ca2a7d6020df8a4c672b3f08dd60..03129a30c325599ed2ee92619aab78a9c7203308 100644
--- a/extensions/common/manifest_constants.cc
+++ b/extensions/common/manifest_constants.cc
@@ -171,6 +171,7 @@ const char kWebview[] = "webview";
 const char kWebviewAccessibleResources[] = "accessible_resources";
 const char kWebviewName[] = "name";
 const char kWebviewPartitions[] = "partitions";
+const char kWhitelist[] = "whitelist";
 
 }  // namespace manifest_keys
 
@@ -330,6 +331,10 @@ const char kInvalidExportResources[] =
     "Invalid value for 'export.resources'.";
 const char kInvalidExportResourcesString[] =
     "Invalid value for 'export.resources[*]'.";
+const char kInvalidExportWhitelist[] =
+    "Invalid value for 'export.whitelist'.";
+const char kInvalidExportWhitelistString[] =
+    "Invalid value for 'export.whitelist[*]'.";
 const char kInvalidFileAccessList[] =
     "Invalid value for 'file_access'.";
 const char kInvalidFileAccessValue[] =