updated .fp file headers

Bug: skia:
Change-Id: I9c39622f34e803a706acd04372be569667380661
Reviewed-on: https://skia-review.googlesource.com/102204
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/effects/GrPremulInputFragmentProcessor.fp b/src/gpu/effects/GrPremulInputFragmentProcessor.fp
index 5a0d6c5..65fd255 100644
--- a/src/gpu/effects/GrPremulInputFragmentProcessor.fp
+++ b/src/gpu/effects/GrPremulInputFragmentProcessor.fp
@@ -1,3 +1,10 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
 @optimizationFlags {
     kPreservesOpaqueInput_OptimizationFlag | kConstantOutputForConstantInput_OptimizationFlag
 }