blimp: Update page load status update indicator to use first paint.

content/renderer/gpu/queue_message_swap_promise.cc

Index: content/renderer/gpu/queue_message_swap_promise.cc
diff --git a/content/renderer/gpu/queue_message_swap_promise.cc b/content/renderer/gpu/queue_message_swap_promise.cc
index 9653375e65ced1d51a0543bbc4a3ce7ca51658d1..8b99a17256c38cac5b7b3f69aa00d9d4eda3f9e4 100644
--- a/content/renderer/gpu/queue_message_swap_promise.cc
+++ b/content/renderer/gpu/queue_message_swap_promise.cc
@@ -4,6 +4,9 @@
 
 #include "content/renderer/gpu/queue_message_swap_promise.h"
 
+#include "base/command_line.h"
+#include "content/public/common/content_switches.h"
+#include "content/public/renderer/render_thread.h"
 #include "content/renderer/gpu/frame_swap_message_queue.h"
 #include "ipc/ipc_sync_message_filter.h"
 
@@ -38,6 +41,20 @@ void QueueMessageSwapPromise::DidActivate() {
 #endif
   message_queue_->DidActivate(source_frame_number_);
   // The OutputSurface will take care of the Drain+Send.
+
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kUseRemoteCompositing)) {
+    // The remote compositing mode doesn't have an output surface, so we need to
+    // Drain+Send on activation. Also, we can't use the SyncMessageFilter, since
+    // this call is actually made on the main thread.
+    std::vector<std::unique_ptr<IPC::Message>> messages_to_deliver;
+    std::unique_ptr<FrameSwapMessageQueue::SendMessageScope>
+        send_message_scope = message_queue_->AcquireSendMessageScope();
+    message_queue_->DrainMessages(&messages_to_deliver);
+    for (auto& message : messages_to_deliver)
+      RenderThread::Get()->Send(message.release());
+    PromiseCompleted();
+  }
 }
 
 void QueueMessageSwapPromise::DidSwap(cc::CompositorFrameMetadata* metadata) {