Allow Crashpad to build in the Chromium tree

build/crashpad_in_chromium.gypi

+# Copyright 2015 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.
+
+{
+  # Crashpad can build as a standalone project or as part of Chromium. When
+  # building as a standalone project, it uses mini_chromium to provide the base
+  # library, and uses its own copy of gtest in third_party. When building as
+  # part of Chromium, it uses Chromium’s base library and copy of gtest. In
+  # order for Crashpad’s .gyp files to reference the correct versions depending
+  # on whether building standalone or as a part of Chromium, include this .gypi
+  # file and reference the crashpad_in_chromium variable.
+
+  'variables': {
+    'variables': {
+      # When building as a standalone project, build/gyp_crashpad.py sets
+      # crashpad_standalone to 1, and this % assignment will not override it.
+      # The variable will not be set when building as part of Chromium, so in
+      # that case, this will define it with value 0.
+      'crashpad_standalone%': 0,
+    },
+
+    'conditions': [
+      ['crashpad_standalone!=0', {
+        'crashpad_in_chromium': 0,
+      }, {
+        'crashpad_in_chromium': 1,
+      }],
+    ],
+
+    'crashpad_in_chromium': '<(crashpad_in_chromium)',
+  },
+}