Revert of Add source column to chrome://policy showing the origins of policies.

Revert of Add source column to chrome://policy showing the origins of policies. (patchset #18 id:620001 of https://codereview.chromium.org/1304843004/ )

Reason for revert:
Fix google chrome compile. http://build.chromium.org/p/chromium.chrome/builders/Google%20Chrome%20Linux%20x64/builds/4220/steps/compile/logs/stdio

../../chrome/browser/ui/startup/startup_browser_creator_browsertest.cc:1235:23:error:
too few arguments to function call, expected 6, have 5
                  NULL);
                      ^
../../components/policy/core/common/policy_map.h:66:3: note: 'Set' declared here
  void Set(const std::string& policy,
  ^

Original issue's description:
> Add source column to chrome://policy showing the origins of policies.
>
> These are the possible sources for a policy:
> Cloud - Policy values received from the cloud.
> Platform - Local configured policies.
> Enterprise Default - Defaults for policies in enterprise environments
>                      on Chrome OS. Can be overridden.
> Enterprise Override - Policies enforced in enterprise environments on
>                       Chrome OS. Can NOT be overridden.
>
> The source of a policy is determined when it's first set. For cloud
> policies, this would be the decoding of the protocol buffers.
> Platform policies are usually set by loading platform-specific local
> configurations like entries in the Windows registry.
> Enterprise defaults are automatically set if the device is active in
> an enterprise environment.
> Enterprise override policies are set within the code to enforce
> specific behaviors (like ash tray visibility). They cannot be
> overridden.
>
> BUG=506123
> TBR=jam@chromium.org
>
> Committed: https://crrev.com/92e7960f06c2ac2ec0113bb88df3d322f0eb97fe
> Cr-Commit-Position: refs/heads/master@{#349654}
>
> Committed: https://crrev.com/2c4ce2a1988fdde3456e49112eba6c7855ca4528
> Cr-Commit-Position: refs/heads/master@{#349749}

TBR=tnagel@chromium.org,bartfab@chromium.org,dbeam@chromium.org,jam@chromium.org,fhorschig@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=506123
Committed: https://crrev.com/c8778b84c83b210d60046b538e9d16cfc1f534cd
Cr-Commit-Position: refs/heads/master@{#349774}

[dgrogan, 2015-09-18 21:27:58]

Created Revert of Add source column to chrome://policy showing the origins of
policies.

[commit-bot: I haz the power, 2015-09-18 21:28:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1350913006/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1350913006/1

[commit-bot: I haz the power, 2015-09-18 21:30:26]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-18 21:31:11]

Patchset 1 (id:??) landed as
https://crrev.com/c8778b84c83b210d60046b538e9d16cfc1f534cd
Cr-Commit-Position: refs/heads/master@{#349774}