Add the crashpad_handler executable

handler/handler.gyp

+# Copyright 2014 The Crashpad Authors. 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.
+
+{
+  'conditions': [
+    ['OS=="mac"', {
+      'targets': [
+        {
+          'target_name': 'crashpad_handler',
+          'type': 'executable',
+          'dependencies': [
+            '../compat/compat.gyp:compat',
+            '../third_party/mini_chromium/mini_chromium/base/base.gyp:base',
+            '../tools/tools.gyp:tool_support',
+            '../util/util.gyp:util',
+          ],
+          'include_dirs': [
+            '..',
+          ],
+          'sources': [
+            'mac/exception_handler_server.cc',
+            'mac/exception_handler_server.h',
+            'mac/main.cc',
+          ],
+        },
+      ],
+    }, {
+      'targets': [],
+    }],
+  ],
+}