Add BubbleManager to manage bubbles and ChromeBubbleManager for events.

components/bubble.gypi

+# Copyright 2015 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.
+
+{
+  'targets': [
+    {
+      # GN version: //components/bubble
+      'target_name': 'bubble',
+      'type': 'static_library',
+      'include_dirs': [
+        '..',
+      ],
+      'sources': [
+        # Note: sources list duplicated in GN build.
+        'bubble/bubble_close_reason.h',
+        'bubble/bubble_controller.cc',
+        'bubble/bubble_controller.h',
+        'bubble/bubble_delegate.cc',
+        'bubble/bubble_delegate.h',
+        'bubble/bubble_manager.cc',
+        'bubble/bubble_manager.h',
+        'bubble/bubble_ui.h',
+      ],
+    },
+  ],
+}