Revert of Update FlatBuffers to include multiple improvements.

Revert of Update FlatBuffers to include multiple improvements. (patchset #5 id:80001 of https://codereview.chromium.org/2883063002/ )

Reason for revert:
Fails "Win" build: https://build.chromium.org/p/chromium/builders/Win/builds/55836

Original issue's description:
> Update FlatBuffers to include multiple improvements.
> 
> This CL updates FlatBuffers to the latest version 1.6.x. This is necessary to
> include the following changes to the library:
>  - d7ac378: Offset<T>::IsNull method.
>  - 93c0960: --keep-prefix compiler option.
>  - c559eb4: Generate files for empty schemas.
>  - aaf5598: Fix path comparison on Windows.
>  - fb87c0d: Improve allocator handling (fixes test).
>  - 22743ca: Fix --keep-prefix bugs.
>  - 642254b: Fix one more --keep-prefix issue.
>  - dd05f32: Add tests for nested FlatBuffers.
>  - 01c50d5: Get rid of move semantics in VectorIterator.
> 
> BUG=611351, 713774
> 
> Review-Url: https://codereview.chromium.org/2883063002
> Cr-Commit-Position: refs/heads/master@{#477254}
> Committed: https://chromium.googlesource.com/chromium/src/+/387b2a94017449569f0f5b2f865d3331e3646a3a

TBR=palmer@chromium.org,engedy@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=611351, 713774
Review-Url: https://codereview.chromium.org/2926563002
Cr-Commit-Position: refs/heads/master@{#477258}
Committed: https://chromium.googlesource.com/chromium/src/+/10a266981d83baf81c3eb24873c8732699ed087e

[pkalinnikov, 2017-06-06 11:32:27]

The CQ bit was checked by pkalinnikov@chromium.org

[pkalinnikov, 2017-06-06 11:32:28]

Created Revert of Update FlatBuffers to include multiple improvements.

[commit-bot: I haz the power, 2017-06-06 11:32:36]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-06-06 11:32:51]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1496748747690160, "parent_rev":
"499d5e9e59c379dcfc4e8d782817246a43ce4130", "commit_rev":
"10a266981d83baf81c3eb24873c8732699ed087e"}

[commit-bot: I haz the power, 2017-06-06 11:33:06]

Description was changed from

==========
Revert of Update FlatBuffers to include multiple improvements. (patchset #5
id:80001 of https://codereview.chromium.org/2883063002/ )

Reason for revert:
Fails "Win" build:
https://build.chromium.org/p/chromium/builders/Win/builds/55836

Original issue's description:
> Update FlatBuffers to include multiple improvements.
> 
> This CL updates FlatBuffers to the latest version 1.6.x. This is necessary to
> include the following changes to the library:
>  - d7ac378: Offset<T>::IsNull method.
>  - 93c0960: --keep-prefix compiler option.
>  - c559eb4: Generate files for empty schemas.
>  - aaf5598: Fix path comparison on Windows.
>  - fb87c0d: Improve allocator handling (fixes test).
>  - 22743ca: Fix --keep-prefix bugs.
>  - 642254b: Fix one more --keep-prefix issue.
>  - dd05f32: Add tests for nested FlatBuffers.
>  - 01c50d5: Get rid of move semantics in VectorIterator.
> 
> BUG=611351,713774
> 
> Review-Url: https://codereview.chromium.org/2883063002
> Cr-Commit-Position: refs/heads/master@{#477254}
> Committed:
https://chromium.googlesource.com/chromium/src/+/387b2a94017449569f0f5b2f865d...

TBR=palmer@chromium.org,engedy@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=611351,713774
==========

to

==========
Revert of Update FlatBuffers to include multiple improvements. (patchset #5
id:80001 of https://codereview.chromium.org/2883063002/ )

Reason for revert:
Fails "Win" build:
https://build.chromium.org/p/chromium/builders/Win/builds/55836

Original issue's description:
> Update FlatBuffers to include multiple improvements.
> 
> This CL updates FlatBuffers to the latest version 1.6.x. This is necessary to
> include the following changes to the library:
>  - d7ac378: Offset<T>::IsNull method.
>  - 93c0960: --keep-prefix compiler option.
>  - c559eb4: Generate files for empty schemas.
>  - aaf5598: Fix path comparison on Windows.
>  - fb87c0d: Improve allocator handling (fixes test).
>  - 22743ca: Fix --keep-prefix bugs.
>  - 642254b: Fix one more --keep-prefix issue.
>  - dd05f32: Add tests for nested FlatBuffers.
>  - 01c50d5: Get rid of move semantics in VectorIterator.
> 
> BUG=611351,713774
> 
> Review-Url: https://codereview.chromium.org/2883063002
> Cr-Commit-Position: refs/heads/master@{#477254}
> Committed:
https://chromium.googlesource.com/chromium/src/+/387b2a94017449569f0f5b2f865d...

TBR=palmer@chromium.org,engedy@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=611351,713774

Review-Url: https://codereview.chromium.org/2926563002
Cr-Commit-Position: refs/heads/master@{#477258}
Committed:
https://chromium.googlesource.com/chromium/src/+/10a266981d83baf81c3eb24873c8...
==========

[commit-bot: I haz the power, 2017-06-06 11:33:07]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/10a266981d83baf81c3eb24873c8...