[ffigen] Rename `master` branch to `main` (#582)

diff --git a/pkgs/ffigen/.github/workflows/test-package.yml b/pkgs/ffigen/.github/workflows/test-package.yml
index 6200394..1ca09eb 100644
--- a/pkgs/ffigen/.github/workflows/test-package.yml
+++ b/pkgs/ffigen/.github/workflows/test-package.yml
@@ -3,9 +3,9 @@
 on:
   # Run on PRs and pushes to the default branch.
   push:
-    branches: [master, stable]
+    branches: [main, stable]
   pull_request:
-    branches: [master, stable]
+    branches: [main, stable]
   schedule:
     - cron: "0 0 * * 0"
 
diff --git a/pkgs/ffigen/README.md b/pkgs/ffigen/README.md
index 674c347..b703655 100644
--- a/pkgs/ffigen/README.md
+++ b/pkgs/ffigen/README.md
@@ -1,6 +1,6 @@
 [![pub package](https://img.shields.io/pub/v/ffigen.svg)](https://pub.dev/packages/ffigen)
 [![Build Status](https://github.com/dart-lang/ffigen/workflows/Dart%20CI/badge.svg)](https://github.com/dart-lang/ffigen/actions?query=workflow%3A"Dart+CI")
-[![Coverage Status](https://coveralls.io/repos/github/dart-lang/ffigen/badge.svg?branch=master)](https://coveralls.io/github/dart-lang/ffigen?branch=master)
+[![Coverage Status](https://coveralls.io/repos/github/dart-lang/ffigen/badge.svg?branch=main)](https://coveralls.io/github/dart-lang/ffigen?branch=main)
 
 Binding generator for [FFI](https://dart.dev/guides/libraries/c-interop) bindings.
 
diff --git a/pkgs/ffigen/example/README.md b/pkgs/ffigen/example/README.md
index 91a8db8..cb1ce8c 100644
--- a/pkgs/ffigen/example/README.md
+++ b/pkgs/ffigen/example/README.md
@@ -1,7 +1,7 @@
 ## Examples
 
-- [Simple](https://github.com/dart-lang/ffigen/tree/master/example/simple)
-- [cJSON](https://github.com/dart-lang/ffigen/tree/master/example/c_json)
-- [LibClang](https://github.com/dart-lang/ffigen/tree/master/example/libclang-example)
-- [ObjectiveC](https://github.com/dart-lang/ffigen/tree/master/example/objective_c)
-- [Swift](https://github.com/dart-lang/ffigen/tree/master/example/swift)
+- [Simple](https://github.com/dart-lang/ffigen/tree/main/example/simple)
+- [cJSON](https://github.com/dart-lang/ffigen/tree/main/example/c_json)
+- [LibClang](https://github.com/dart-lang/ffigen/tree/main/example/libclang-example)
+- [ObjectiveC](https://github.com/dart-lang/ffigen/tree/main/example/objective_c)
+- [Swift](https://github.com/dart-lang/ffigen/tree/main/example/swift)
diff --git a/pkgs/ffigen/test/README.md b/pkgs/ffigen/test/README.md
index cfcc314..dc57474 100644
--- a/pkgs/ffigen/test/README.md
+++ b/pkgs/ffigen/test/README.md
@@ -1,5 +1,5 @@
 [![Build Status](https://github.com/dart-lang/ffigen/workflows/Dart%20CI/badge.svg)](https://github.com/dart-lang/ffigen/actions?query=workflow%3A"Dart+CI")
-[![Coverage Status](https://coveralls.io/repos/github/dart-lang/ffigen/badge.svg?branch=master)](https://coveralls.io/github/dart-lang/ffigen?branch=master)
+[![Coverage Status](https://coveralls.io/repos/github/dart-lang/ffigen/badge.svg?branch=main)](https://coveralls.io/github/dart-lang/ffigen?branch=main)
 
 # ffigen testing
 
@@ -23,18 +23,18 @@
 Some tests verify that the generated Dart FFI bindings match a golden file.
 
 For example, the test
-[`test/native_test/native_test.dart`](https://github.com/dart-lang/ffigen/blob/master/test/native_test/native_test.dart)
+[`test/native_test/native_test.dart`](https://github.com/dart-lang/ffigen/blob/main/test/native_test/native_test.dart)
 works by:
 
 1.  Loading the dynamic library for
-    [`test/native_test/native_test.c`](https://github.com/dart-lang/ffigen/blob/master/test/native_test/native_test.c)
+    [`test/native_test/native_test.c`](https://github.com/dart-lang/ffigen/blob/main/test/native_test/native_test.c)
     (which was generated by `dart run test/setup.dart`).
 
 2.  Generating binding files for that dynamic library in the
     `test/debug_generated` directory.
 
 3.  Comparing the golden file (i.e.
-    [`test/native_test/_expected_native_test_bindings.dart`](https://github.com/dart-lang/ffigen/blob/master/test/native_test/_expected_native_test_bindings.dart))
+    [`test/native_test/_expected_native_test_bindings.dart`](https://github.com/dart-lang/ffigen/blob/main/test/native_test/_expected_native_test_bindings.dart))
     to the generated file and generating a test failure if they do not match.
 
 4.  Using the *golden* bindings to excercise the dynamic library.