Remove CreateEmptyExtension from extension_function_test_utils

extensions/common/test_util.h

Index: extensions/common/test_util.h
diff --git a/extensions/common/test_util.h b/extensions/common/test_util.h
index 46ac5d08c3f266ee773e84ed878a611a3b16dd74..83a09047e74deeb54e3ebf2e05849c8f2d15a013 100644
--- a/extensions/common/test_util.h
+++ b/extensions/common/test_util.h
@@ -27,8 +27,9 @@ ExtensionBuilder& BuildExtension(ExtensionBuilder& builder);
 // before running it.
 scoped_refptr<Extension> CreateEmptyExtension();
 
-// Return a very simple extension with a given |id|.
-scoped_refptr<Extension> CreateExtensionWithID(const std::string& id);
+// Create an extension with a variable |id|, for tests that require multiple
+// extensions side-by-side having distinct IDs.
+scoped_refptr<Extension> CreateEmptyExtension(const std::string& id);
 
 // Parses |json| allowing trailing commas and replacing single quotes with
 // double quotes for test readability. If the json fails to parse, calls gtest's