Add support for loading API keys from Info.plist on iOS and macOS.

google_apis/google_api_keys_unittest.h

+// 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.
+
+#ifndef GOOGLE_APIS_GOOGLE_API_KEYS_UNITTEST_H_
+#define GOOGLE_APIS_GOOGLE_API_KEYS_UNITTEST_H_
+
+#include <memory>
+#include <string>
+
+#include "base/environment.h"
+#include "google_apis/google_api_keys.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+struct EnvironmentCache {
+  EnvironmentCache() : variable_name(nullptr), was_set(false) {}
+
+  const char* variable_name;
+  bool was_set;
+  std::string value;
+};
+
+class GoogleAPIKeysTest : public testing::Test {
+ public:
+  GoogleAPIKeysTest();
+  ~GoogleAPIKeysTest() override;
+  void SetUp() override;
+  void TearDown() override;
+
+ private:
+  std::unique_ptr<base::Environment> env_;
+
+  // Why 3?  It is for GOOGLE_API_KEY, GOOGLE_DEFAULT_CLIENT_ID and
+  // GOOGLE_DEFAULT_CLIENT_SECRET.
+  //
+  // Why 2 times CLIENT_NUM_ITEMS?  This is the number of different
+  // clients in the OAuth2Client enumeration, and for each of these we
+  // have both an ID and a secret.
+  EnvironmentCache env_cache_[3 + 2 * google_apis::CLIENT_NUM_ITEMS];
+};
+
+#endif  // GOOGLE_APIS_GOOGLE_API_KEYS_UNITTEST_H_