[mojo-edk] Expose portable API for platform handle wrapping

mojo/edk/embedder/platform_shared_buffer.cc

Index: mojo/edk/embedder/platform_shared_buffer.cc
diff --git a/mojo/edk/embedder/platform_shared_buffer.cc b/mojo/edk/embedder/platform_shared_buffer.cc
index 467e5e6a8a184204473264bb60690ce42f63b856..12f9940845a09b7139b05678dc148be18b28f69b 100644
--- a/mojo/edk/embedder/platform_shared_buffer.cc
+++ b/mojo/edk/embedder/platform_shared_buffer.cc
@@ -18,22 +18,6 @@
 namespace mojo {
 namespace edk {
 
-namespace {
-
-// Takes ownership of |memory_handle|.
-ScopedPlatformHandle SharedMemoryToPlatformHandle(
-    base::SharedMemoryHandle memory_handle) {
-#if defined(OS_POSIX) && !(defined(OS_MACOSX) && !defined(OS_IOS))
-  return ScopedPlatformHandle(PlatformHandle(memory_handle.fd));
-#elif defined(OS_WIN)
-  return ScopedPlatformHandle(PlatformHandle(memory_handle.GetHandle()));
-#else
-  return ScopedPlatformHandle(PlatformHandle(memory_handle.GetMemoryObject()));
-#endif
-}
-
-}  // namespace
-
 // static
 PlatformSharedBuffer* PlatformSharedBuffer::Create(size_t num_bytes) {
   DCHECK_GT(num_bytes, 0u);
@@ -101,6 +85,37 @@ PlatformSharedBuffer* PlatformSharedBuffer::CreateFromSharedMemoryHandle(
   return rv;
 }
 
+// static
+base::SharedMemoryHandle
+PlatformSharedBuffer::GetSharedMemoryHandleFromPlatformHandle(
+      MojoPlatformHandle platform_handle,
+      size_t size,
+      bool read_only) {
+#if defined(OS_POSIX) && !(defined(OS_MACOSX) && !defined(OS_IOS))
+  return base::SharedMemoryHandle(static_cast<int>(platform_handle),
+                                  false);
+#elif defined(OS_WIN)
+  return base::SharedMemoryHandle(static_cast<HANDLE>(platform_handle),
+                                  base::GetCurrentProcessHandle());
+#else
+  return base::SharedMemoryHandle(static_cast<mach_port_t>(platform_handle),
+                                  static_cast<mach_vm_size_t>(num_bytes),
+                                  base::GetCurrentProcId());
+#endif
+}
+
+// static
+PlatformHandle PlatformSharedBuffer::GetPlatformHandleFromSharedMemoryHandle(
+    base::SharedMemoryHandle memory_handle) {
+#if defined(OS_POSIX) && !(defined(OS_MACOSX) && !defined(OS_IOS))
+  return PlatformHandle(memory_handle.fd);
+#elif defined(OS_WIN)
+  return PlatformHandle(memory_handle.GetHandle());
+#else
+  return PlatformHandle(memory_handle.GetMemoryObject());
+#endif
+}
+
 size_t PlatformSharedBuffer::GetNumBytes() const {
   return num_bytes_;
 }
@@ -161,7 +176,7 @@ ScopedPlatformHandle PlatformSharedBuffer::DuplicatePlatformHandle() {
   if (handle == base::SharedMemory::NULLHandle())
     return ScopedPlatformHandle();
 
-  return SharedMemoryToPlatformHandle(handle);
+  return ScopedPlatformHandle(GetPlatformHandleFromSharedMemoryHandle(handle));
 }
 
 ScopedPlatformHandle PlatformSharedBuffer::PassPlatformHandle() {