cherry pick g3 fix to release branch (#3138)

INTERNAL
* Remove duplicate declaration. (#3030)

BUG Remove duplicate declaration.

* Add license. (#3027)

BUG Add license to pad3d.ts.

Co-authored-by: Na Li <linazhao@google.com>

Author: pyu10055

tfjs-core/src/ops/pad3d.ts

@@ -1,3 +1,19 @@
+/**
+ * @license
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * =============================================================================
+ */
 import {Tensor3D} from '../tensor';
 import {TensorLike} from '../types';
 import {assert} from '../util';

tfjs-core/src/ops/rand_util.ts

@@ -286,21 +286,3 @@ function skewness(values: TypedArray|number[]) {
   }
   return (1 / n) * sum3 / Math.pow((1 / (n - 1)) * sum2, 3 / 2);
 }
-
-export interface RandomBase {
-  nextValue(): number;
-}
-
-export interface RandomGamma {
-  nextValue(): number;
-}
-
-export interface RandNormalDataTypes {
-  float32: Float32Array;
-  int32: Int32Array;
-}
-
-export interface RandGammaDataTypes {
-  float32: Float32Array;
-  int32: Int32Array;
-}