Revert of base::Time should correctly handle -epoch time values from Javascript

Revert of base::Time should correctly handle -epoch time values from Javascript (patchset #1 id:1 of https://codereview.chromium.org/2593073002/ )

Reason for revert:
The patched broke EME player which was relying on null time being converted to 0 in FromJsTime.

After discussing this, we agreed to try to change all conversion methods together to ensure consistency. A precursor to doing this will be to get stop treating zero as null.


For more info see:  https://bugs.chromium.org/p/chromium/issues/detail?id=679079#c13

Original issue's description:
> Correctly handle -epoch time values when converting from JS time to base::Time
> 
> -11644473600 seconds (which represents windows epoch time of
> |1601-01-01 00:00:00 UTC|) is a valid time value in Javascript. Incidentally
> this value is internally represented by 0 which is mistakenly confused with a
> null time value.
> 
> FromJsTime is meant to be used to convert time values coming from Javascript
> for which 0 or -epoch do not represent null values. So the extra check was
> incorrect.
> 
> * In fact there is a comment in FromJsTime method making it clear that 0 is a
> valid value but this was missed in ToJsTime method.
> 
> TEST=./base_unittests --gtest_filter=TimeTest.JsTime
> 
> BUG=625680
> 
> Committed: https://crrev.com/6650abf280f2987af809b0111ad00e5dba5723e4
> Cr-Commit-Position: refs/heads/master@{#440304}

TBR=miu@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=625680
Review-Url: https://codereview.chromium.org/2655233003
Cr-Commit-Position: refs/heads/master@{#446340}
Committed: https://chromium.googlesource.com/chromium/src/+/7ff9ceb9be03477632e2808268882889ff551185

[majidvp, 2017-01-26 15:07:42]

The CQ bit was checked by majidvp@chromium.org

[majidvp, 2017-01-26 15:07:42]

Created Revert of base::Time should correctly handle -epoch time values from
Javascript

[commit-bot: I haz the power, 2017-01-26 15:07:50]

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, 2017-01-26 16:13:47]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1485443262340480, "parent_rev":
"59c132dd68c72b0f8af750465d1d8032efdbba0b", "commit_rev":
"7ff9ceb9be03477632e2808268882889ff551185"}

[commit-bot: I haz the power, 2017-01-26 16:14:22]

Description was changed from

==========
Revert of base::Time should correctly handle -epoch time values from Javascript
(patchset #1 id:1 of https://codereview.chromium.org/2593073002/ )

Reason for revert:
The patched broke EME player which was relying on null time being converted to 0
in FromJsTime.

After discussing this, we agreed to try to change all conversion methods
together to ensure consistency. A precursor to doing this will be to get stop
treating zero as null.


For more info see: 
https://bugs.chromium.org/p/chromium/issues/detail?id=679079#c13

Original issue's description:
> Correctly handle -epoch time values when converting from JS time to base::Time
> 
> -11644473600 seconds (which represents windows epoch time of
> |1601-01-01 00:00:00 UTC|) is a valid time value in Javascript. Incidentally
> this value is internally represented by 0 which is mistakenly confused with a
> null time value.
> 
> FromJsTime is meant to be used to convert time values coming from Javascript
> for which 0 or -epoch do not represent null values. So the extra check was
> incorrect.
> 
> * In fact there is a comment in FromJsTime method making it clear that 0 is a
> valid value but this was missed in ToJsTime method.
> 
> TEST=./base_unittests --gtest_filter=TimeTest.JsTime
> 
> BUG=625680
> 
> Committed: https://crrev.com/6650abf280f2987af809b0111ad00e5dba5723e4
> Cr-Commit-Position: refs/heads/master@{#440304}

TBR=miu@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=625680
==========

to

==========
Revert of base::Time should correctly handle -epoch time values from Javascript
(patchset #1 id:1 of https://codereview.chromium.org/2593073002/ )

Reason for revert:
The patched broke EME player which was relying on null time being converted to 0
in FromJsTime.

After discussing this, we agreed to try to change all conversion methods
together to ensure consistency. A precursor to doing this will be to get stop
treating zero as null.


For more info see: 
https://bugs.chromium.org/p/chromium/issues/detail?id=679079#c13

Original issue's description:
> Correctly handle -epoch time values when converting from JS time to base::Time
> 
> -11644473600 seconds (which represents windows epoch time of
> |1601-01-01 00:00:00 UTC|) is a valid time value in Javascript. Incidentally
> this value is internally represented by 0 which is mistakenly confused with a
> null time value.
> 
> FromJsTime is meant to be used to convert time values coming from Javascript
> for which 0 or -epoch do not represent null values. So the extra check was
> incorrect.
> 
> * In fact there is a comment in FromJsTime method making it clear that 0 is a
> valid value but this was missed in ToJsTime method.
> 
> TEST=./base_unittests --gtest_filter=TimeTest.JsTime
> 
> BUG=625680
> 
> Committed: https://crrev.com/6650abf280f2987af809b0111ad00e5dba5723e4
> Cr-Commit-Position: refs/heads/master@{#440304}

TBR=miu@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=625680

Review-Url: https://codereview.chromium.org/2655233003
Cr-Commit-Position: refs/heads/master@{#446340}
Committed:
https://chromium.googlesource.com/chromium/src/+/7ff9ceb9be03477632e280826888...
==========

[commit-bot: I haz the power, 2017-01-26 16:14:23]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/7ff9ceb9be03477632e280826888...