Revert of Let ImeAdapterAndroid have the same lifecycle as its Java peer (patchset #12 id:340001 of https://codereview.chromium.org/2752113005/ )

Reason for revert:
Suspected breaking Marshmallow 64 bit tester: https://uberchromegw.corp.google.com/i/chromium.android/builders/Marshmallow%2064%20bit%20Tester/builds/10654

Original issue's description:
> Let ImeAdapterAndroid have the same lifecycle as its Java peer
>
> The native ImeAdapterAndroid(IAA) instance is owned by
> RenderWidgetHostViewAndroid(RWHVA) while its Java peer
> (ImeAdapter) is owned by CVC. This causes their life
> cycles to be different. Attach/detach API are used to get them
> linked before talking to each other.
>
> This CL makes this mechanism simpler by having Java ImeAdapter
> class create the native together, hence gets their lifetime synced.
> The separate attach/detach mechanism is not necessary since
> the linking is done as a part of WCVA - RWHVA association job.
> i.e. IAA is linked to the current RWHVA when the corresponding
> CVCImpl is set to RWHVA (in the future this will be done separately
> as RWHVA will be rid of all the references to CVC).
>
> The only situation where the linking should be done "manually"
> is when IAA gets (temporarily) linked to RWHVA for an interstitial
> page. The link between IAA and the main RWHVA gets restored
> once the interstitial page is detached.
>
> BUG=662908
>
> Review-Url: https://codereview.chromium.org/2752113005
> Cr-Commit-Position: refs/heads/master@{#460028}
> Committed: https://chromium.googlesource.com/chromium/src/+/153d2811b3cbcf69cda7ab4817cdc35e7c680dee

[email protected],[email protected],[email protected],[email protected],[email protected]
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=662908

Review-Url: https://codereview.chromium.org/2785543003
Cr-Commit-Position: refs/heads/master@{#460247}
16 files changed