Mojo: Add a platform interface for shared memory (embedder::PlatformSharedBuffer).

mojo/system/dispatcher.cc

Index: mojo/system/dispatcher.cc
diff --git a/mojo/system/dispatcher.cc b/mojo/system/dispatcher.cc
index 18d9be86454010ac697752ff614f5b6444005ba0..263ca2961315d25c1540b4954b49d4878e39a2a6 100644
--- a/mojo/system/dispatcher.cc
+++ b/mojo/system/dispatcher.cc
@@ -199,10 +199,11 @@ MojoResult Dispatcher::DuplicateBufferHandle(
   return DuplicateBufferHandleImplNoLock(options, new_dispatcher);
 }
 
-MojoResult Dispatcher::MapBuffer(uint64_t offset,
-                                 uint64_t num_bytes,
-                                 MojoMapBufferFlags flags,
-                                 scoped_ptr<RawSharedBufferMapping>* mapping) {
+MojoResult Dispatcher::MapBuffer(
+    uint64_t offset,
+    uint64_t num_bytes,
+    MojoMapBufferFlags flags,
+    scoped_ptr<embedder::PlatformSharedBufferMapping>* mapping) {
   base::AutoLock locker(lock_);
   if (is_closed_)
     return MOJO_RESULT_INVALID_ARGUMENT;
@@ -353,7 +354,7 @@ MojoResult Dispatcher::MapBufferImplNoLock(
     uint64_t /*offset*/,
     uint64_t /*num_bytes*/,
     MojoMapBufferFlags /*flags*/,
-    scoped_ptr<RawSharedBufferMapping>* /*mapping*/) {
+    scoped_ptr<embedder::PlatformSharedBufferMapping>* /*mapping*/) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, not supported. Only needed for buffer dispatchers.