Add license text and update headers, similar to lit/lit#1630 .

Author: bicknellr

LICENSE

@@ -0,0 +1,28 @@
+BSD 3-Clause License
+
+Copyright (c) 2021 Google LLC. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

package.json

@@ -24,7 +24,7 @@
     "url": "git+https://github.com/webcomponents/template-shadowroot.git"
   },
   "keywords": [],
-  "author": "The Polymer Authors",
+  "author": "Google LLC",
   "license": "BSD-3-Clause",
   "bugs": {
     "url": "https://github.com/webcomponents/template-shadowroot/issues"

src/_implementation/default_implementation.ts

@@ -1,15 +1,7 @@
 /**
  * @license
- * Copyright (c) 2020 The Polymer Project Authors. All rights reserved.
- * This code may only be used under the BSD style license found at
- * http://polymer.github.io/LICENSE.txt
- * The complete set of authors may be found at
- * http://polymer.github.io/AUTHORS.txt
- * The complete set of contributors may be found at
- * http://polymer.github.io/CONTRIBUTORS.txt
- * Code distributed by Google as part of the polymer project is also
- * subject to an additional IP rights grant found at
- * http://polymer.github.io/PATENTS.txt
+ * Copyright 2020 Google LLC
+ * SPDX-License-Identifier: BSD-3-Clause
  */
 
 // TODO(rictic): do more robust benchmarks and pick a winner.

src/_implementation/feature_detect.ts

@@ -1,15 +1,7 @@
 /**
  * @license
- * Copyright (c) 2020 The Polymer Project Authors. All rights reserved.
- * This code may only be used under the BSD style license found at
- * http://polymer.github.io/LICENSE.txt
- * The complete set of authors may be found at
- * http://polymer.github.io/AUTHORS.txt
- * The complete set of contributors may be found at
- * http://polymer.github.io/CONTRIBUTORS.txt
- * Code distributed by Google as part of the polymer project is also
- * subject to an additional IP rights grant found at
- * http://polymer.github.io/PATENTS.txt
+ * Copyright 2020 Google LLC
+ * SPDX-License-Identifier: BSD-3-Clause
  */
 
 // This isn't ideal. Setting .innerHTML is not compatible with some

src/_implementation/manual_walk.ts

@@ -1,15 +1,7 @@
 /**
  * @license
- * Copyright (c) 2019 The Polymer Project Authors. All rights reserved.
- * This code may only be used under the BSD style license found at
- * http://polymer.github.io/LICENSE.txt
- * The complete set of authors may be found at
- * http://polymer.github.io/AUTHORS.txt
- * The complete set of contributors may be found at
- * http://polymer.github.io/CONTRIBUTORS.txt
- * Code distributed by Google as part of the polymer project is also
- * subject to an additional IP rights grant found at
- * http://polymer.github.io/PATENTS.txt
+ * Copyright 2019 Google LLC
+ * SPDX-License-Identifier: BSD-3-Clause
  */
 
 import {hasNativeDeclarativeShadowRoots} from './feature_detect.js';

src/_implementation/mutation_observer.ts

@@ -1,15 +1,7 @@
 /**
  * @license
- * Copyright (c) 2020 The Polymer Project Authors. All rights reserved.
- * This code may only be used under the BSD style license found at
- * http://polymer.github.io/LICENSE.txt
- * The complete set of authors may be found at
- * http://polymer.github.io/AUTHORS.txt
- * The complete set of contributors may be found at
- * http://polymer.github.io/CONTRIBUTORS.txt
- * Code distributed by Google as part of the polymer project is also
- * subject to an additional IP rights grant found at
- * http://polymer.github.io/PATENTS.txt
+ * Copyright 2020 Google LLC
+ * SPDX-License-Identifier: BSD-3-Clause
  */
 
 import {hydrateShadowRoots} from './default_implementation.js';

src/_implementation/queryselectorall.ts

@@ -1,15 +1,7 @@
 /**
  * @license
- * Copyright (c) 2020 The Polymer Project Authors. All rights reserved.
- * This code may only be used under the BSD style license found at
- * http://polymer.github.io/LICENSE.txt
- * The complete set of authors may be found at
- * http://polymer.github.io/AUTHORS.txt
- * The complete set of contributors may be found at
- * http://polymer.github.io/CONTRIBUTORS.txt
- * Code distributed by Google as part of the polymer project is also
- * subject to an additional IP rights grant found at
- * http://polymer.github.io/PATENTS.txt
+ * Copyright 2020 Google LLC
+ * SPDX-License-Identifier: BSD-3-Clause
  */
 
 import {hasNativeDeclarativeShadowRoots} from './feature_detect.js';

src/_implementation/util.ts

@@ -1,15 +1,7 @@
 /**
  * @license
- * Copyright (c) 2019 The Polymer Project Authors. All rights reserved.
- * This code may only be used under the BSD style license found at
- * http://polymer.github.io/LICENSE.txt
- * The complete set of authors may be found at
- * http://polymer.github.io/AUTHORS.txt
- * The complete set of contributors may be found at
- * http://polymer.github.io/CONTRIBUTORS.txt
- * Code distributed by Google as part of the polymer project is also
- * subject to an additional IP rights grant found at
- * http://polymer.github.io/PATENTS.txt
+ * Copyright 2019 Google LLC
+ * SPDX-License-Identifier: BSD-3-Clause
  */
 
 export const hasNoParentElement =

src/template-shadowroot.ts

@@ -1,15 +1,7 @@
 /**
  * @license
- * Copyright (c) 2019 The Polymer Project Authors. All rights reserved.
- * This code may only be used under the BSD style license found at
- * http://polymer.github.io/LICENSE.txt
- * The complete set of authors may be found at
- * http://polymer.github.io/AUTHORS.txt
- * The complete set of contributors may be found at
- * http://polymer.github.io/CONTRIBUTORS.txt
- * Code distributed by Google as part of the polymer project is also
- * subject to an additional IP rights grant found at
- * http://polymer.github.io/PATENTS.txt
+ * Copyright 2019 Google LLC
+ * SPDX-License-Identifier: BSD-3-Clause
  */
 
 import {hasNativeDeclarativeShadowRoots} from './_implementation/feature_detect.js';

src/test/template-shadowroot_test.ts

@@ -1,15 +1,7 @@
 /**
  * @license
- * Copyright (c) 2019 The Polymer Project Authors. All rights reserved.
- * This code may only be used under the BSD style license found at
- * http://polymer.github.io/LICENSE.txt
- * The complete set of authors may be found at
- * http://polymer.github.io/AUTHORS.txt
- * The complete set of contributors may be found at
- * http://polymer.github.io/CONTRIBUTORS.txt
- * Code distributed by Google as part of the polymer project is also
- * subject to an additional IP rights grant found at
- * http://polymer.github.io/PATENTS.txt
+ * Copyright 2019 Google LLC
+ * SPDX-License-Identifier: BSD-3-Clause
  */
 
 import {hydrateShadowRoots as manualWalkHydration} from '../_implementation/manual_walk.js';