Remove DCHECKs that no longer reflect reality.

Remove DCHECKs that no longer reflect reality.

It used to be that CreateEntropyProvider() was only
called once in a process, during the init sequence,
and then never again. So previously, these DCHECKs
could never fire by virtue of the function always
being called once.

Now that this function is called by VariationsService
when simulating new variations seeds, it will be
called multiple times during the process life time.
It's perfectly valid to return an entropy provider
that uses a different entropy source in that context
(e.g. post changing your UMA opt-in setting), since
that's exactly what the simulation code wants (i.e.
it simulates what will happen on a restart).

So simply remove the checks, since their conditions
no longer hold.

BUG=405010
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=290706

[Ilya Sherman, 2014-08-19 21:04:14]

https://codereview.chromium.org/492463002/diff/1/components/metrics/metrics_s...
File components/metrics/metrics_state_manager.cc (left):

https://codereview.chromium.org/492463002/diff/1/components/metrics/metrics_s...
components/metrics/metrics_state_manager.cc:164: entropy_source_returned_ =
ENTROPY_SOURCE_HIGH;
Is this if stmt, as well as the one below, still correct?

[Alexei Svitkine (slow), 2014-08-19 21:10:25]

https://codereview.chromium.org/492463002/diff/1/components/metrics/metrics_s...
File components/metrics/metrics_state_manager.cc (left):

https://codereview.chromium.org/492463002/diff/1/components/metrics/metrics_s...
components/metrics/metrics_state_manager.cc:164: entropy_source_returned_ =
ENTROPY_SOURCE_HIGH;
On 2014/08/19 21:04:14, Ilya Sherman wrote:
> Is this if stmt, as well as the one below, still correct?

Yes, the field is documented to track the first value returned.

[Ilya Sherman, 2014-08-19 21:55:40]

Alrighty.  LGTM.

[Alexei Svitkine (slow), 2014-08-19 22:07:01]

The CQ bit was checked by asvitkine@chromium.org

[commit-bot: I haz the power, 2014-08-19 22:12:16]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/asvitkine@chromium.org/492463002/1

[commit-bot: I haz the power, 2014-08-19 23:15:59]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  win_chromium_compile_dbg on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_comp...)
  win_chromium_rel_swarming on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[commit-bot: I haz the power, 2014-08-20 00:04:58]

Committed patchset #1 (1) as 290706