Revert of Architecture for cross-process memory notification suppressing (patchset #11 id:240001 of https://codereview.chromium.org/1332583002/ )

Reason for revert:
This seems to cause failure in Cast Linux: content_browsertests: MemoryPressureControllerBrowserTest.SetPressureNotificationsSuppressedInAllProcesses

Original issue's description:
> Architecture for cross-process memory notification suppressing
>
> This patch adds IPC architecture for suppressing memory pressure
> notifications in all processes:
>
>               BROWSER PROCESS                    CHILD PROCESSES
>
>          MemoryPressureListener::           MemoryPressureListener::
>         SetNotificationsSuppressed         SetNotificationsSuppressed
>         (existing static method*)          (existing static method*)
>                      ^                                  ^
>                      |                                  |
>        +--------------------------+                     |
>        | MemoryPressureController |                     |
>   +..> |        (singleton)       |                     |
>   :    +--------------------------+                     |
>   :                  |                                  |
>   :                  V                                  |
>   :    +--------------------------+       +--------------------------+
>   :    |    MemoryMessageFilter   | <===> | ChildMemoryMessageFilter |
>   :    |    (per child process)   |  IPC  |        (singleton)       |
>   :    +--------------------------+       +--------------------------+
>   :
>   :
>   +.. Memory.setPressureNotificationsSuppressed
>               (proposed DevTools API**)
>
> *)  The required functionality for individual processes was added in:
>     https://codereview.chromium.org/1312163003.
> **) The new DevTools API will be added in the following 3-sided patch:
>     https://codereview.chromium.org/1336363002,
>     https://codereview.chromium.org/1311343007, and
>     https://codereview.chromium.org/1342833004.
>
> This patch adds new message filters on both sides (MemoryMessageFilter
> in the browser process and ChildMemoryMessageFilter in the child
> process) because we anticipate more functionality to be added to
> MemoryPressureController in the near future (methods for simulating
> memory pressure signals and, more importantly, propagating memory
> pressure signals to all processes on desktop Chrome). Encapsulating the
> relevant IPC communication in dedicated message filters is arguably
> better than keeping augmenting (and having duplicate code in)
> BrowserChildProcessHostImpl, RenderProcessHostImpl, and
> ChildThreadImpl.
>
> This patch represents the second step towards implementing a DevTools
> API for suppressing and simulating memory pressure signals in Chrome.
> The main use case for this feature is to enforce consistent conditions
> across memory measurements. See https://goo.gl/cZFdH3 for more details.
>
> BUG=516776
>
> Committed: https://crrev.com/0b119f3392d6c6169bbb792347a04f34ce649156
> Cr-Commit-Position: refs/heads/master@{#350169}

TBR=skyostil@chromium.org,primiano@chromium.org,nasko@chromium.org,chrisha@chromium.org,petrcermak@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=516776

Review URL: https://codereview.chromium.org/1359873002

Cr-Commit-Position: refs/heads/master@{#350175}

1 files changed, 0 insertions, 1 deletions

diff --git a/ipc/ipc_message_start.h b/ipc/ipc_message_start.h
index bf93b94..718bfa7 100644
--- a/ipc/ipc_message_start.h
+++ b/ipc/ipc_message_start.h
@@ -126,7 +126,6 @@ enum IPCMessageStart {
   AttachmentBrokerMsgStart,
   RenderProcessMsgStart,
   PageLoadMetricsMsgStart,
-  MemoryMsgStart,
   LastIPCMsgStart  // Must come last.
 };