Disable ECKEncryptedMediaTest.FileIOTest

TBR=sergeyu@chromium.org

Bug: 997953
Change-Id: I6d8e98aefa6d37a556d295b9cbc115ef94572797
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1773259Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#690747}

chrome/browser/media/encrypted_media_browsertest.cc

@@ -829,7 +829,8 @@ IN_PROC_BROWSER_TEST_P(ECKEncryptedMediaTest, DISABLED_CDMCrashDuringDecode) {
                        kEmeSessionClosedAndError);
 }
 
-IN_PROC_BROWSER_TEST_P(ECKEncryptedMediaTest, FileIOTest) {
+// Flaky: crbug.com/997953
+IN_PROC_BROWSER_TEST_P(ECKEncryptedMediaTest, DISABLED_FileIOTest) {
   TestNonPlaybackCases(kExternalClearKeyFileIOTestKeySystem, kUnitTestSuccess);
 }