Reland of rotate frames correctly for back camera

media/capture/video/linux/camera_facing_chromeos_unittest.cc

+// 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.
+
+#include <string>
+
+#include "media/capture/video/linux/camera_facing_chromeos.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+#include <base/files/file_util.h>
+#include <base/files/file.h>
+
+namespace media {
+
+namespace {
+
+const char kConfigFileContent[] =
+    "camera0.lens_facing=1\ncamera0.sensor_orientation=0\ncamera0.module0.usb_"
+    "vid_pid=04f2:b53a\n";
+}
+
+TEST(CameraFacingChromeOSTest, ParseSuccessfully) {
+  const char file_name[] = "fake_camera_characteristics.conf";
+  base::WriteFile(base::FilePath(file_name), kConfigFileContent,
+                  sizeof(kConfigFileContent));
+
+  std::string file_name_str(file_name);
+  CameraFacingChromeOS camera_facing(file_name_str);
+  EXPECT_EQ(CameraFacingChromeOS::LensFacing::BACK,
+            camera_facing.GetCameraFacing(std::string("/dev/video2"),
+                                          std::string("04f2:b53a")));
+}
+
+TEST(CameraFacingChromeOSTest, ConfigFileNotExist) {
+  CameraFacingChromeOS camera_facing(std::string("file_not_exist"));
+  EXPECT_EQ(CameraFacingChromeOS::LensFacing::FRONT,
+            camera_facing.GetCameraFacing(std::string("/dev/video2"),
+                                          std::string("04f2:b53a")));
+}
+
+}  // namespace media