Add documentation for MemoryCoordinator-related primitives

base/memory/memory_coordinator_client.h

Index: base/memory/memory_coordinator_client.h
diff --git a/base/memory/memory_coordinator_client.h b/base/memory/memory_coordinator_client.h
index d24d3e7cd102cceadf24b227e9761cee8a834ee3..2049f8ff8e282042dd25a55488ad16cfde7303d8 100644
--- a/base/memory/memory_coordinator_client.h
+++ b/base/memory/memory_coordinator_client.h
@@ -24,7 +24,9 @@ namespace base {
 // memory state. Note that clients aren't expected to free up memory on memory
 // state changes. Clients should wait for a separate purge request to free up
 // memory. Purging requests will be throttled as well.
-
+//
+// See //base/memory/memory_coordinator.md for the replacement plan.

[Ryan Sleevi, 2017/02/25 02:57:10]

I don't think memory_coordinator.md is really "the replacement plan", but rather
the "How to use them"

That is, it gives no information about how the replacement will look other than
there is a plan :)

+//
 // MemoryState is an indicator that processes can use to guide their memory
 // allocation policies. For example, a process that receives the throttled
 // state can use that as as signal to decrease memory cache limits.