Move mojo edk into mojo/edk

This creates a mojo/edk directory which contains the "embedder developer
kit" aka the set of code needed to embed mojo code.

mojo/edk/embedder = code from mojo/embedder
mojo/edk/system = code from mojo/system
mojo/edk/test = code used to test the previous two, from mojo/common/test

mojo/edk/ can only depend on mojo/public/, base/ and itself.

R=viettrungluu@chromium.org
TBR=sky@chromium.org for file renames

Committed: https://chromium.googlesource.com/chromium/src/+/ee7ff197a98da4636f33bd713de784948b487bd4

Review URL: https://codereview.chromium.org/621153003

Cr-Commit-Position: refs/heads/master@{#297986}


CrOS-Libchrome-Original-Commit: a03ae49d253d7d1f517e2f92146a6ba201c78aa6
diff --git a/ipc/mojo/ipc_channel_mojo_unittest.cc b/ipc/mojo/ipc_channel_mojo_unittest.cc
index ac1efd1..39224a0 100644
--- a/ipc/mojo/ipc_channel_mojo_unittest.cc
+++ b/ipc/mojo/ipc_channel_mojo_unittest.cc
@@ -239,7 +239,7 @@
   CreateChannel(&listener);
   ASSERT_TRUE(ConnectChannel());
 
-  // This matches a value in mojo/system/constants.h
+  // This matches a value in mojo/edk/system/constants.h
   const int kMaxMessageNumBytes = 4 * 1024 * 1024;
   std::string overly_large_data(kMaxMessageNumBytes, '*');
   // This messages are queued as pending.