Removing dependency to service manager from ChildProcessServiceImpl.

Moving the retrieval of FD keys used to register FDs to the
FileDescriptorStore from ChildProcessServiceImpl to
ContentChildProcessServiceDelegate, as these depend on ServiceManager.
This require introducing a new call to ChildProcessServiceDelegate and
having one extra JNI call done during process start-up.

TBR=michaelbai

Bug: 702316
Change-Id: I3d39d68440b3d16033bd6bd9ccbe6b51241325e1
Reviewed-on: https://chromium-review.googlesource.com/538906
Commit-Queue: Jay Civelli <jcivelli@chromium.org>
Reviewed-by: Bo Liu <boliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#481378}
5 files changed