Revert of Reland of Migrate DeviceUtils.ReadFile to adb_wrapper

Revert of Reland of Migrate DeviceUtils.ReadFile to adb_wrapper (patchset #3 id:40001 of https://codereview.chromium.org/794583004/)

Reason for revert:
Broke again android perf bots and nexus 7 debug with error:

CRITICAL:root:Cannot set Chrome command line. Fix this by flashing to a userdebug build.

Original issue's description:
> Reland of Migrate DeviceUtils.ReadFile to adb_wrapper
>
> Original description:
>
> The implementation is based on a simple 'cat' run by shell on the
> device (with optional as_root).
>
> Interface changes:
> - The return value is a string (instead of a list of lines).
> - An exception is raised if the file cannot be read
>   (instead of returning an empty list).
>
> Original CL: https://codereview.chromium.org/775333002/
>
> BUG=267773
>
> Committed: https://crrev.com/a8d3b82a9c779568ee64ec5c261c6c7024ef8759
> Cr-Commit-Position: refs/heads/master@{#307881}

TBR=jbudorick@chromium.org,skyostil@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=267773
Committed: https://crrev.com/a485981c9e60877f4a7435c3726eb19149b52589
Cr-Commit-Position: refs/heads/master@{#307904}

[perezju, 2014-12-11 15:53:31]

Created Revert of Reland of Migrate DeviceUtils.ReadFile to adb_wrapper

[commit-bot: I haz the power, 2014-12-11 15:54:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/796013004/1

[commit-bot: I haz the power, 2014-12-11 15:54:13]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-12-11 15:54:14]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[jbudorick, 2014-12-11 16:04:35]

lgtm

[perezju, 2014-12-11 16:04:58]

The CQ bit was checked by perezju@chromium.org

[commit-bot: I haz the power, 2014-12-11 16:05:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/796013004/1

[commit-bot: I haz the power, 2014-12-11 16:06:15]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-12-11 16:07:08]

Patchset 1 (id:??) landed as
https://crrev.com/a485981c9e60877f4a7435c3726eb19149b52589
Cr-Commit-Position: refs/heads/master@{#307904}