Reland of "Moves mojo_js_integration_tests into blink."

This reverts commit c461e58ee3a426a1064c83895f9320ff94121712.

Reason for revert: JsToCpp.mojom.js should now be available on android devices when running webkit_unit_tests: https://chromium-review.googlesource.com/c/540085/

Original change's description:
> Revert "Reland of Moves mojo_js_integration_tests into blink. (patchset #1 id:1 of https://codereview.chromium.org/2939663002/ )"
>
> Reason for revert:
> WebKit Android (Nexus4) are still broken with four failing tests:
>   JsToCppTest.BackPointer
>   JsToCppTest.BitFlip
>   JsToCppTest.Ping
>   JsToCppTest.Echo
>
> TBR=jbroman@chromium.org,dpranke@chromium.org,yzshen@chromium.org,jwd@chromium.org,alokp@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=699569
>
> Change-Id: I925840dbe50bd21e6c87b03f23d6b4007d27df63
> Reviewed-on: https://chromium-review.googlesource.com/538520
> Reviewed-by: Daniel Cheng <dcheng@chromium.org>
> Commit-Queue: Daniel Cheng <dcheng@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#480282}

TBR=dcheng@chromium.org,jwd@chromium.org,jbroman@chromium.org,dpranke@chromium.org,yzshen@chromium.org,agrieve@chromium.org,alokp@chromium.org

Bug: 699569
Change-Id: I59bcce1f0a4f650eedaea7cce999b650041e7506
Reviewed-on: https://chromium-review.googlesource.com/540664
Commit-Queue: Alok Priyadarshi <alokp@chromium.org>
Reviewed-by: Alok Priyadarshi <alokp@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#481712}
14 files changed