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

mojo/edk/system/platform_handle_dispatcher.cc

Index: mojo/edk/system/platform_handle_dispatcher.cc
diff --git a/third_party/mojo/src/mojo/edk/system/platform_handle_dispatcher.cc b/mojo/edk/system/platform_handle_dispatcher.cc
similarity index 94%
copy from third_party/mojo/src/mojo/edk/system/platform_handle_dispatcher.cc
copy to mojo/edk/system/platform_handle_dispatcher.cc
index 681b40686344d6a6ee3433b9210317f84bfa41e6..a6f830512abb1c2eed3c56dcbb7d1fae7260e9c9 100644
--- a/third_party/mojo/src/mojo/edk/system/platform_handle_dispatcher.cc
+++ b/mojo/edk/system/platform_handle_dispatcher.cc
@@ -15,14 +15,14 @@ namespace {
 
 const size_t kInvalidPlatformHandleIndex = static_cast<size_t>(-1);
 
-struct SerializedPlatformHandleDispatcher {
+struct MOJO_ALIGNAS(8) SerializedPlatformHandleDispatcher {
   size_t platform_handle_index;  // (Or |kInvalidPlatformHandleIndex|.)
 };
 
 }  // namespace
 
 embedder::ScopedPlatformHandle PlatformHandleDispatcher::PassPlatformHandle() {
-  MutexLocker locker(&mutex());
+  base::AutoLock locker(lock());
   return platform_handle_.Pass();
 }
 
@@ -32,7 +32,6 @@ Dispatcher::Type PlatformHandleDispatcher::GetType() const {
 
 // static
 scoped_refptr<PlatformHandleDispatcher> PlatformHandleDispatcher::Deserialize(
-    Channel* channel,
     const void* source,
     size_t size,
     embedder::PlatformHandleVector* platform_handles) {
@@ -73,18 +72,17 @@ PlatformHandleDispatcher::~PlatformHandleDispatcher() {
 }
 
 void PlatformHandleDispatcher::CloseImplNoLock() {
-  mutex().AssertHeld();
+  lock().AssertAcquired();
   platform_handle_.reset();
 }
 
 scoped_refptr<Dispatcher>
 PlatformHandleDispatcher::CreateEquivalentDispatcherAndCloseImplNoLock() {
-  mutex().AssertHeld();
+  lock().AssertAcquired();
   return Create(platform_handle_.Pass());
 }
 
 void PlatformHandleDispatcher::StartSerializeImplNoLock(
-    Channel* /*channel*/,
     size_t* max_size,
     size_t* max_platform_handles) {
   DCHECK(HasOneRef());  // Only one ref => no need to take the lock.
@@ -93,7 +91,6 @@ void PlatformHandleDispatcher::StartSerializeImplNoLock(
 }
 
 bool PlatformHandleDispatcher::EndSerializeAndCloseImplNoLock(
-    Channel* /*channel*/,
     void* destination,
     size_t* actual_size,
     embedder::PlatformHandleVector* platform_handles) {