File Unbundle-gtest.patch of Package libgav1

--- a/tests/libgav1_tests.cmake	2022-06-30 20:41:58.000000000 +0000
+++ b/tests/libgav1_tests.cmake	2023-04-29 13:01:10.517636900 +0000
@@ -12,28 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-if(LIBGAV1_LIBGAV1_TESTS_CMAKE_)
-  return()
-endif() # LIBGAV1_LIBGAV1_TESTS_CMAKE_
-set(LIBGAV1_LIBGAV1_TESTS_CMAKE_ 1)
-
-set(libgav1_googletest "${libgav1_root}/third_party/googletest")
-if(NOT LIBGAV1_ENABLE_TESTS OR NOT EXISTS "${libgav1_googletest}")
-  macro(libgav1_add_tests_targets)
-
-  endmacro()
-
-  if(LIBGAV1_ENABLE_TESTS AND NOT EXISTS "${libgav1_googletest}")
-    message(
-      "GoogleTest not found, setting LIBGAV1_ENABLE_TESTS to false.\n"
-      "To enable tests download the GoogleTest repository to"
-      " third_party/googletest:\n\n  git \\\n    -C ${libgav1_root} \\\n"
-      "    clone \\\n"
-      "    https://github.com/google/googletest.git third_party/googletest\n")
-    set(LIBGAV1_ENABLE_TESTS FALSE CACHE BOOL "Enables tests." FORCE)
-  endif()
-  return()
-endif()
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(gtest REQUIRED gtest)
+pkg_check_modules(gtest_main REQUIRED gtest_main)
 
 # Check GoogleTest compiler requirements.
 if((CMAKE_CXX_COMPILER_ID
@@ -195,31 +176,20 @@
         "This version of libgav1_add_tests_targets() should only be used with"
         " LIBGAV1_ENABLE_TESTS set to true.")
   endif()
-  libgav1_add_library(TEST
-                      NAME
-                      libgav1_gtest
-                      TYPE
-                      STATIC
-                      SOURCES
-                      "${libgav1_googletest}/googletest/src/gtest-all.cc"
-                      DEFINES
-                      ${libgav1_defines}
-                      INCLUDES
-                      ${libgav1_gtest_include_paths}
-                      ${libgav1_include_paths})
-
-  libgav1_add_library(TEST
-                      NAME
-                      libgav1_gtest_main
-                      TYPE
-                      STATIC
-                      SOURCES
-                      "${libgav1_googletest}/googletest/src/gtest_main.cc"
-                      DEFINES
-                      ${libgav1_defines}
-                      INCLUDES
-                      ${libgav1_gtest_include_paths}
-                      ${libgav1_include_paths})
+
+  add_library(libgav1_gtest INTERFACE)
+  target_link_libraries(libgav1_gtest INTERFACE ${gtest_LIBRARIES})
+  target_link_directories(libgav1_gtest INTERFACE ${gtest_LIBRARY_DIRS})
+  target_link_options(libgav1_gtest INTERFACE ${gtest_LDFLAGS_OTHER})
+  target_include_directories(libgav1_gtest INTERFACE ${gtest_INCLUDE_DIRS})
+  target_compile_options(libgav1_gtest INTERFACE ${gtest_CFLAGS_OTHER})
+
+  add_library(libgav1_gtest_main INTERFACE)
+  target_link_libraries(libgav1_gtest_main INTERFACE ${gtest_main_LIBRARIES})
+  target_link_directories(libgav1_gtest_main INTERFACE ${gtest_main_LIBRARY_DIRS})
+  target_link_options(libgav1_gtest_main INTERFACE ${gtest_main_LDFLAGS_OTHER})
+  target_include_directories(libgav1_gtest_main INTERFACE ${gtest_main_INCLUDE_DIRS})
+  target_compile_options(libgav1_gtest_main INTERFACE ${gtest_main_CFLAGS_OTHER})
 
   if(use_absl_threading)
     list(APPEND libgav1_common_test_absl_deps absl::synchronization)