Revert of Straightens outs DEPS in mojo/common (patchset #5 id:80001 of https://coder...

Revert of Straightens outs DEPS in mojo/common (patchset #5 id:80001 of https://codereview.chromium.org/1262173005/ )

Reason for revert:
Broke MediaRouterMojoImplTest.QueuedWhileAsleep on linux debug.

Original issue's description:
> Straightens outs DEPS in mojo/common
>
> Prior to this change //mojo/environment depended upon //mojo/common. //mojo/common's deps are wrong and it needs to be depend upon various things in //third_party/mojo/src/mojo... When these DEPS are added link errors result because Environment and and a couple of other things need to be defined. These are defined in //mojo/environment. But //mojo/environment can't be a dep of //mojo/common, else we get a cycle.
>
> To straighten this out I've moved the files //mojo/environment needs from //mojo/common to //mojo/message_pump. //mojo/environment no longer depends upon //mojo/common, only //mojo/message_pump. //mojo/common can then depend upon //mojo/environment and we no longer have the cycle. Yay!
>
> BUG=none
> TEST=none
>
> Committed: https://crrev.com/a11b4d76a27816fe025af647825becac5f633c34
> Cr-Commit-Position: refs/heads/master@{#341979}

TBR=jam@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=none

Review URL: https://codereview.chromium.org/1280463003

Cr-Commit-Position: refs/heads/master@{#342014}