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

ipc/mojo/scoped_ipc_support.cc

Index: ipc/mojo/scoped_ipc_support.cc
diff --git a/ipc/mojo/scoped_ipc_support.cc b/ipc/mojo/scoped_ipc_support.cc
index b1d530e0463aedfe7c4e18f13a9aa94e31142395..0d9253990a898a8a2dcbf829ea42b2cd1f407333 100644
--- a/ipc/mojo/scoped_ipc_support.cc
+++ b/ipc/mojo/scoped_ipc_support.cc
@@ -12,14 +12,23 @@
 #include "base/synchronization/lock.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/thread_task_runner_handle.h"
+
+#if defined(USE_CHROME_EDK)
+#include "mojo/edk/embedder/embedder.h"
+#include "mojo/edk/embedder/process_delegate.h"
+#else
 #include "third_party/mojo/src/mojo/edk/embedder/embedder.h"
 #include "third_party/mojo/src/mojo/edk/embedder/process_delegate.h"
+#endif
 
 namespace IPC {
 
 namespace {
-
+#if defined(USE_CHROME_EDK)
+class IPCSupportInitializer : public mojo::edk::ProcessDelegate {
+#else
 class IPCSupportInitializer : public mojo::embedder::ProcessDelegate {
+#endif
  public:
   IPCSupportInitializer()
       : init_count_(0),
@@ -105,9 +114,16 @@ void IPCSupportInitializer::Init(
     io_thread_task_runner_ = io_thread_task_runner;
     io_thread_task_runner_->PostTask(
         FROM_HERE, base::Bind(&WatchMessageLoopOnIOThread, observer_));
+
+#if defined(USE_CHROME_EDK)
+    mojo::edk::InitIPCSupport(
+        io_thread_task_runner_, this, io_thread_task_runner_,
+        mojo::edk::ScopedPlatformHandle());
+#else
     mojo::embedder::InitIPCSupport(
-        mojo::embedder::ProcessType::NONE, io_thread_task_runner_, this,
-        io_thread_task_runner_, mojo::embedder::ScopedPlatformHandle());
+        mojo::embedder::ProcessType::NONE, io_thread_task_runner_, this, io_thread_task_runner_,
+        mojo::embedder::ScopedPlatformHandle());
+#endif
   }
 }
 
@@ -144,7 +160,11 @@ void IPCSupportInitializer::ForceShutdown() {
 void IPCSupportInitializer::ShutDownOnIOThread() {
   base::AutoLock locker(lock_);
   if (shutting_down_ && !was_shut_down_) {
+#if defined(USE_CHROME_EDK)
+    mojo::edk::ShutdownIPCSupportOnIOThread();
+#else
     mojo::embedder::ShutdownIPCSupportOnIOThread();
+#endif
     init_count_ = 0;
     shutting_down_ = false;
     io_thread_task_runner_ = nullptr;