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

mojo/runner/context.h

Index: mojo/runner/context.h
diff --git a/mojo/runner/context.h b/mojo/runner/context.h
index 5667385f3b3ad544e135b488de50ccd1838dff4f..845e39c8eaaa579d9aaef255ec3bc4992224fe1f 100644
--- a/mojo/runner/context.h
+++ b/mojo/runner/context.h
@@ -11,12 +11,17 @@
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/time/time.h"
-#include "mojo/edk/embedder/process_delegate.h"
 #include "mojo/runner/scoped_user_data_dir.h"
 #include "mojo/runner/task_runners.h"
 #include "mojo/shell/application_manager.h"
 #include "url/gurl.h"
 
+#if defined(USE_CHROME_EDK)
+#include "mojo/edk/embedder/process_delegate.h"
+#else
+#include "third_party/mojo/src/mojo/edk/embedder/process_delegate.h"
+#endif
+
 namespace mojo {
 namespace package_manager {
 class PackageManagerImpl;
@@ -26,7 +31,11 @@ namespace runner {
 class NativeApplicationLoader;
 
 // The "global" context for the shell's main process.
+#if defined(USE_CHROME_EDK)
+class Context : public edk::ProcessDelegate {
+#else
 class Context : public embedder::ProcessDelegate {
+#endif
  public:
   explicit Context(const base::FilePath& shell_file_root);
   ~Context() override;