Add the copresence component.

components/copresence.gypi

+# Copyright 2014 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': [
+    {
+      'target_name': 'copresence',
+      'type': 'static_library',
+      'dependencies': [
+        '../base/base.gyp:base',
+        '../net/net.gyp:net',
+        'copresence_proto',
+      ],
+      'include_dirs': [
+        '..',
+      ],
+      'defines': [

[jochen (gone - plz use gerrit), 2014/07/30 09:29:00]

nit. remove empty blocks

[rkc, 2014/07/30 10:16:45]

I was following what feedback.gypi had, so thought this may be needed for some
reason :) Removed.
Done.

+      ],
+      'sources': [
+        'copresence/copresence_client.cc',
+        'copresence/copresence_client.h',
+        'copresence/interface/copresence_delegate.h',
+        'copresence/interface/whispernet_client.h',
+        'copresence/rpc/rpc_handler.cc',
+        'copresence/rpc/rpc_handler.h',
+      ],
+      'export_dependent_settings': [
+        'copresence_proto',
+      ],
+    },
+    {
+      # Protobuf compiler / generate rule for copresence.
+      # GN version: //components/copresence/proto
+      # Note: These protos are auto-generated from the protos of the
+      # Copresence server. Currently this strips all formatting and comments
+      # but makes sure that we are always using up to date protos.
+      'target_name': 'copresence_proto',
+      'type': 'static_library',
+      'sources': [
+        'copresence/proto/codes.proto',
+        'copresence/proto/data.proto',
+        'copresence/proto/enums.proto',
+        'copresence/proto/identity.proto',
+        'copresence/proto/rpcs.proto',
+      ],
+      'variables': {
+        'proto_in_dir': 'copresence/proto',
+        'proto_out_dir': 'components/copresence/proto',
+      },
+      'includes': [ '../build/protoc.gypi' ]
+    },
+  ],
+}