Flush gcda (code coverage) files manually in iOS Platform Test.

testing/coverage_util_ios.cc

Index: testing/coverage_util_ios.cc
diff --git a/ui/ozone/common/gpu/ozone_gpu_message_generator.h b/testing/coverage_util_ios.cc
similarity index 57%
copy from ui/ozone/common/gpu/ozone_gpu_message_generator.h
copy to testing/coverage_util_ios.cc
index 3b35c0e7bcedef014f02657b6b52c7d2de512f00..15ac1b4a0a89a99b700d6c2e24624db753805602 100644
--- a/ui/ozone/common/gpu/ozone_gpu_message_generator.h
+++ b/testing/coverage_util_ios.cc
@@ -2,6 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Multiply-included file, hence no include guard.
+extern "C" void __gcov_flush();
 
-#include "ui/ozone/common/gpu/ozone_gpu_messages.h"
+namespace coverage_util {
+
+void FlushCoverageDataIfNecessary() {
+#if defined(ENABLE_TEST_CODE_COVERAGE)
+  __gcov_flush();
+#endif
+}
+
+}  // namespace coverage_util