This is required to provide a reasonably feature-comnplete
implementation of current org.chromium.net APIs on top of
android.net.http. The main targets for this change are gRPC (mostly
bidirectional streaming) and prospective early adopters.
Test: m
API-Coverage-Bug: 251012627
Change-Id: I66341581501090641c7eea32de5a5b8453cd97d4
HttpEngine.getVersion() can be implemented directly as the API and implementation versions don't differ in AOSP.
Test: m
Change-Id: Ide6881f8978cb8890d585f760cd0d1225a4c2542