Revert of Adding total available size of heap in v8 isolate memory dump provider.

Revert of Adding total available size of heap in v8 isolate memory dump provider. (patchset #1 id:1 of https://codereview.chromium.org/1129403003/)

Reason for revert:
The HeapStatistics::total_available_size returned by v8 API doesn't return the correct value right now. It only returns the sum of available size of 4 spaces only. So, this should land after the API gets fixed.

Original issue's description:
> Adding total available size of heap in v8 isolate memory dump provider.
>
> The total available size is now returned by GetHeapStatistics api.
> This CL uses the value in the dump provider to show the value in
> other_spaces segment of the memory dump.
>
> BUG=481504
>
> Committed: https://crrev.com/9ad94e6e06201059c08d67b9d9ab4a30a766b541
> Cr-Commit-Position: refs/heads/master@{#329303}

TBR=jochen@chromium.org,picksi@chromium.org,primiano@chromium.org
BUG=481504
Committed: https://crrev.com/b765e2ad9225ecca8c89d535870365d33e9a728f
Cr-Commit-Position: refs/heads/master@{#329479}

[ssid, 2015-05-12 16:19:31]

Created Revert of Adding total available size of heap in v8 isolate memory dump
provider.

[ssid, 2015-05-12 16:20:04]

Sorry, there was an error in API, which I just realized.

[Primiano Tucci (use gerrit), 2015-05-12 16:38:11]

LGTM.
P.S. I removed the NOTRY / NOTREECHECKS for you as this is not fixing a build
breakage.

[ssid, 2015-05-12 19:44:21]

The CQ bit was checked by ssid@chromium.org

[commit-bot: I haz the power, 2015-05-12 19:45:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1134233002/1

[commit-bot: I haz the power, 2015-05-12 20:46:26]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-12 20:47:44]

Patchset 1 (id:??) landed as
https://crrev.com/b765e2ad9225ecca8c89d535870365d33e9a728f
Cr-Commit-Position: refs/heads/master@{#329479}