Implement MojoGetBufferInformation(), part 1.

mojo/edk/system/dispatcher.h

Index: mojo/edk/system/dispatcher.h
diff --git a/mojo/edk/system/dispatcher.h b/mojo/edk/system/dispatcher.h
index 30dd83551568633e0431bc1d95ad998d1d068fad..ccfb9e9dd68169e33581f9dfb9bce0c0096a98c7 100644
--- a/mojo/edk/system/dispatcher.h
+++ b/mojo/edk/system/dispatcher.h
@@ -116,6 +116,8 @@ class Dispatcher : public util::RefCountedThreadSafe<Dispatcher> {
   MojoResult DuplicateBufferHandle(
       UserPointer<const MojoDuplicateBufferHandleOptions> options,
       util::RefPtr<Dispatcher>* new_dispatcher);
+  MojoResult GetBufferInformation(UserPointer<MojoBufferInformation> info,
+                                  uint32_t info_num_bytes);
   MojoResult MapBuffer(
       uint64_t offset,
       uint64_t num_bytes,
@@ -265,6 +267,9 @@ class Dispatcher : public util::RefCountedThreadSafe<Dispatcher> {
       UserPointer<const MojoDuplicateBufferHandleOptions> options,
       util::RefPtr<Dispatcher>* new_dispatcher)
       MOJO_EXCLUSIVE_LOCKS_REQUIRED(mutex_);
+  virtual MojoResult GetBufferInformationImplNoLock(
+      UserPointer<MojoBufferInformation> info,
+      uint32_t info_num_bytes) MOJO_EXCLUSIVE_LOCKS_REQUIRED(mutex_);
   virtual MojoResult MapBufferImplNoLock(
       uint64_t offset,
       uint64_t num_bytes,