Revert of Moves mojo_js_integration_tests into blink. (patchset #1 id:1 of https://codereview.chromium.org/2920383004/ )

Reason for revert:
This CL seems to break webkit_unittests.
The error log is:
https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Mac10.10/builds/34695

The tests below were timed out:
JsToCppTest.BackPointer
JsToCppTest.BitFlip
JsToCppTest.Echo
JsToCppTest.Ping

Original issue's description:
> Reland of Moves mojo_js_integration_tests into blink. (patchset #1 id:1 of https://codereview.chromium.org/2926143002/ )
>
> Reason for revert:
> Fixed failing tests.
>
> Original issue's description:
> > Revert of Moves mojo_js_integration_tests into blink. (patchset #11 id:190001 of https://codereview.chromium.org/2734783008/ )
> >
> > Reason for revert:
> > Seems related to webkit failures of the JsToCpp tests. E.x. https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Mac10.10/builds/34530.
> >
> > Original issue's description:
> > > Moves mojo_js_integration_tests into blink.
> > >
> > > BUG=699569
> > >
> > > Review-Url: https://codereview.chromium.org/2734783008
> > > Cr-Commit-Position: refs/heads/master@{#477549}
> > > Committed: https://chromium.googlesource.com/chromium/src/+/dd57fa764813de09d159a232eeef1bb21b0ccc1e
> >
> > TBR=jbroman@chromium.org,dpranke@chromium.org,yzshen@chromium.org,alokp@chromium.org
> > # Skipping CQ checks because original CL landed less than 1 days ago.
> > NOPRESUBMIT=true
> > NOTREECHECKS=true
> > NOTRY=true
> > BUG=699569
> >
> > Review-Url: https://codereview.chromium.org/2926143002
> > Cr-Commit-Position: refs/heads/master@{#477653}
> > Committed: https://chromium.googlesource.com/chromium/src/+/6536a56d25c245bd109e32ed49240bfc04f8890f
>
> TBR=jbroman@chromium.org,dpranke@chromium.org,yzshen@chromium.org,jwd@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=699569
>
> Review-Url: https://codereview.chromium.org/2920383004
> Cr-Commit-Position: refs/heads/master@{#478820}
> Committed: https://chromium.googlesource.com/chromium/src/+/0fac10b6b0a132a25eedf971c8ccffaa6e8a4961

TBR=jbroman@chromium.org,dpranke@chromium.org,yzshen@chromium.org,jwd@chromium.org,alokp@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=699569

Review-Url: https://codereview.chromium.org/2939663002
Cr-Commit-Position: refs/heads/master@{#478881}
14 files changed