Mojo C++ bindings: make ipc/ mojom targets to use STL string/vector types

ipc/ipc_channel_mojo.cc

Index: ipc/ipc_channel_mojo.cc
diff --git a/ipc/ipc_channel_mojo.cc b/ipc/ipc_channel_mojo.cc
index 9ce2e661bd145a204ca7f62dfa7e68b494c029ed..627efc1dc54f1b7abd9aba0add6247bcce0cce88 100644
--- a/ipc/ipc_channel_mojo.cc
+++ b/ipc/ipc_channel_mojo.cc
@@ -179,7 +179,7 @@ MojoResult WrapAttachmentImpl(MessageAttachment* attachment,
 }
 
 MojoResult WrapAttachment(MessageAttachment* attachment,
-                          mojo::Array<mojom::SerializedHandlePtr>* handles) {
+                          std::vector<mojom::SerializedHandlePtr>* handles) {
   mojom::SerializedHandlePtr serialized_handle;
   MojoResult wrap_result = WrapAttachmentImpl(attachment, &serialized_handle);
   if (wrap_result != MOJO_RESULT_OK) {
@@ -409,38 +409,46 @@ base::ScopedFD ChannelMojo::TakeClientFileDescriptor() {
 // static
 MojoResult ChannelMojo::ReadFromMessageAttachmentSet(
     Message* message,
-    mojo::Array<mojom::SerializedHandlePtr>* handles) {
-  if (message->HasAttachments()) {
-    MessageAttachmentSet* set = message->attachment_set();
-    for (unsigned i = 0; i < set->num_non_brokerable_attachments(); ++i) {
-      MojoResult result = WrapAttachment(
-              set->GetNonBrokerableAttachmentAt(i).get(), handles);
-      if (result != MOJO_RESULT_OK) {
-        set->CommitAllDescriptors();
-        return result;
-      }
-    }
-    for (unsigned i = 0; i < set->num_brokerable_attachments(); ++i) {
-      MojoResult result =
-          WrapAttachment(set->GetBrokerableAttachmentAt(i).get(), handles);
-      if (result != MOJO_RESULT_OK) {
-        set->CommitAllDescriptors();
-        return result;
-      }
-    }
-    set->CommitAllDescriptors();
+    base::Optional<std::vector<mojom::SerializedHandlePtr>>* handles) {
+  DCHECK(!*handles);
+
+  MojoResult result = MOJO_RESULT_OK;
+  if (!message->HasAttachments())
+    return result;
+
+  std::vector<mojom::SerializedHandlePtr> output_handles;
+  MessageAttachmentSet* set = message->attachment_set();
+
+  for (unsigned i = 0;
+       result == MOJO_RESULT_OK && i < set->num_non_brokerable_attachments();
+       ++i) {
+    result = WrapAttachment(set->GetNonBrokerableAttachmentAt(i).get(),
+                            &output_handles);
   }
-  return MOJO_RESULT_OK;
+  for (unsigned i = 0;
+       result == MOJO_RESULT_OK && i < set->num_brokerable_attachments(); ++i) {
+    result = WrapAttachment(set->GetBrokerableAttachmentAt(i).get(),
+                            &output_handles);
+  }
+
+  set->CommitAllDescriptors();
+
+  if (!output_handles.empty())
+    *handles = std::move(output_handles);
+
+  return result;
 }
 
 // static
 MojoResult ChannelMojo::WriteToMessageAttachmentSet(
-    mojo::Array<mojom::SerializedHandlePtr> handle_buffer,
+    base::Optional<std::vector<mojom::SerializedHandlePtr>> handle_buffer,
     Message* message) {
-  for (size_t i = 0; i < handle_buffer.size(); ++i) {
+  if (!handle_buffer)
+    return MOJO_RESULT_OK;
+  for (size_t i = 0; i < handle_buffer->size(); ++i) {
     scoped_refptr<MessageAttachment> unwrapped_attachment;
-    MojoResult unwrap_result = UnwrapAttachment(std::move(handle_buffer[i]),
-                                                    &unwrapped_attachment);
+    MojoResult unwrap_result =
+        UnwrapAttachment(std::move((*handle_buffer)[i]), &unwrapped_attachment);
     if (unwrap_result != MOJO_RESULT_OK) {
       LOG(WARNING) << "Pipe failed to unwrap handles. Closing: "
                    << unwrap_result;