Add a Mojo EDK for Chrome that uses one OS pipe per message pipe.

mojo/edk/embedder/platform_channel_pair.h

Index: mojo/edk/embedder/platform_channel_pair.h
diff --git a/third_party/mojo/src/mojo/edk/embedder/platform_channel_pair.h b/mojo/edk/embedder/platform_channel_pair.h
similarity index 98%
copy from third_party/mojo/src/mojo/edk/embedder/platform_channel_pair.h
copy to mojo/edk/embedder/platform_channel_pair.h
index 873df04437bda06596f98317e79abcf64f9fa92f..74878370fa99423219894ed42ebc868d54b36fe6 100644
--- a/third_party/mojo/src/mojo/edk/embedder/platform_channel_pair.h
+++ b/mojo/edk/embedder/platform_channel_pair.h
@@ -17,7 +17,7 @@ class CommandLine;
 }
 
 namespace mojo {
-namespace embedder {
+namespace edk {
 
 // It would be nice to refactor base/process/launch.h to have a more platform-
 // independent way of representing handles that are passed to child processes.
@@ -88,7 +88,7 @@ class MOJO_SYSTEM_IMPL_EXPORT PlatformChannelPair {
   MOJO_DISALLOW_COPY_AND_ASSIGN(PlatformChannelPair);
 };
 
-}  // namespace embedder
+}  // namespace edk
 }  // namespace mojo
 
 #endif  // MOJO_EDK_EMBEDDER_PLATFORM_CHANNEL_PAIR_H_