Delete memory manager dead code.

Delete memory manager dead code.

There have existed two paths in the memory manager for
a few months -- the old path which uniformly distributes
all memory across all visible renderers, and the new path
which takes into account the needs of each renderer.

The transition was made from the old policy to the new
policy quite a while ago, so we can safely get rid of
the old policy.

BUG=150883
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=187678

[ccameron, 2013-03-06 21:16:14]

A sort run-down of the changes is:

Inside the GpuMemoryManager, this is everything that is
under use_nonuniform_memory_policy_.

Remove the flags for setting use_nonuniform_memory_policy_ to
false.

Remove the gpu_util::BrowserMonitor. It is used to
communicate the number of windows to the GpuMemoryManager,
which is not used except when !use_nonuniform_memory_policy_.

Remove tests that use only the !use_nonuniform_memory_policy_
path and remove the "Nonuniform" from the equivalent tests'
names.

[piman, 2013-03-06 22:07:09]

LGTM. Note, you'll need other OWNERS for stuff in chrome/ and for IPCs.

[ccameron, 2013-03-08 19:28:33]

Adding ben for chrome/ review.
Adding tsepez for IPC review.

[Tom Sepez, 2013-03-09 00:21:47]

LGTM on deleting code.

[Ben Goodger (Google), 2013-03-11 16:25:12]

lgtm

[ccameron, 2013-03-11 22:53:25]

Thanks!!

[commit-bot: I haz the power, 2013-03-11 22:56:01]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ccameron@chromium.org/12475002/10001

[commit-bot: I haz the power, 2013-03-12 01:37:47]

Sorry for I got bad news for ya.
Compile failed with a clobber build on linux_chromeos_clang.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_chro...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[commit-bot: I haz the power, 2013-03-12 17:58:48]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ccameron@chromium.org/12475002/28001

[commit-bot: I haz the power, 2013-03-12 22:57:30]

Change committed as 187678