Decompose //extensions/browser/BUILD.gn

extensions/browser/api/webcam_private/BUILD.gn

Index: extensions/browser/api/webcam_private/BUILD.gn
diff --git a/extensions/browser/api/webcam_private/BUILD.gn b/extensions/browser/api/webcam_private/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..41fc55bc596a0f49ff1e51775e77f5784ceb306c
--- /dev/null
+++ b/extensions/browser/api/webcam_private/BUILD.gn
@@ -0,0 +1,20 @@
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+source_set("webcam_private") {
+  sources = [
+    "v4l2_webcam.cc",
+    "v4l2_webcam.h",
+    "visca_webcam.cc",
+    "visca_webcam.h",
+    "webcam.cc",
+    "webcam.h",
+    "webcam_private_api.h",
+    "webcam_private_api_chromeos.cc",
+  ]
+
+  deps = [
+    "//extensions/common/api",
+  ]
+}