There are many tests that are not annotated with @OnlyRunNativeCronet and are supposed to run both with the native Cronet and Java implementations. However, they are run twice with the Cronet implementation instead.

The solution that is implemented inside CronetTestBase.java works only if CronetTestFramework is instantiated in the test SetUp() method. Instantiating CronetTestFramework directly inside the tests leads to double execution of the Cronet native implementation. CronetTestBase#runTest() is supposed to substitute the native Cronet implementation with Java implementation between the two test runs by assigning JavaCronetEngine implementation to CronetTestFramework.mCronetEngine field. This substitution does not work if a test is calling one of startCronetTestFrameworkXXX() methods.

There are YY calls from tests that are not annotated with @OnlyRunNativeCronet:
17 calls to startCronetTestFramework() 
5 calls to startCronetTestFrameworkWithUrlAndCronetEngineBuilder()
4 calls to startCronetTestFrameworkWithUrlAndCommandLineArgs()
12 calls to startCronetTestFrameworkAndSkipLibraryInit()
6 calls to startCronetTestFrameworkForLegacyApi()