compositor: Fix texture flipping for SW mirroring with surfaceless

content/browser/compositor/reflector_impl.cc

Index: content/browser/compositor/reflector_impl.cc
diff --git a/content/browser/compositor/reflector_impl.cc b/content/browser/compositor/reflector_impl.cc
index ac3bdda748e0d8c56bf346ddb3f4a73ec643f08d..e04edcd07406b5ff83e241b4b48d2fd86ddce6d9 100644
--- a/content/browser/compositor/reflector_impl.cc
+++ b/content/browser/compositor/reflector_impl.cc
@@ -23,7 +23,8 @@ ReflectorImpl::ReflectorImpl(
       main_unsafe_(mirrored_compositor, mirroring_layer),
       impl_message_loop_(compositor_thread_loop),
       main_message_loop_(base::MessageLoopProxy::current()),
-      surface_id_(surface_id) {
+      surface_id_(surface_id),
+      flip_texture_(false) {
   GLHelper* helper = ImageTransportFactory::GetInstance()->GetGLHelper();
   MainThreadData& main = GetMain();
   main.mailbox = new OwnedMailbox(helper);
@@ -183,6 +184,7 @@ void ReflectorImpl::AttachToOutputSurfaceOnImplThread(
   if (impl.output_surface)
     DetachFromOutputSurface();
   impl.output_surface = output_surface;
+  flip_texture_ = !output_surface->capabilities().flipped_output_surface;

[danakj, 2015/01/12 18:27:30]

This is getting the flipped-ness of the current output surface, but setting
flipped for the texture mailbox, which came from a different output surface,
right? How can you guarantee that these match?

[achaulk, 2015/01/12 18:47:35]

All that matters is the flipped-ness of the source surface, since that's where
the texture contents are coming from. This ensures that the layer contains the
same data either way (normal painting and flipped=true or inverted painting and
flipped=false). The properties of the output surface for the mirroring layer
shouldn't matter

[danakj, 2015/01/12 19:02:42]

Oh this is the source surface? OK great :) I read it as the target surface at
first!

   output_surface->context_provider()->BindToCurrentThread();
   impl.gl_helper.reset(
       new GLHelper(output_surface->context_provider()->ContextGL(),
@@ -215,6 +217,7 @@ void ReflectorImpl::UpdateTextureSizeOnMainThread(gfx::Size size) {
     main.mirroring_layer->SetTextureSize(size);
   }
   main.mirroring_layer->SetBounds(gfx::Rect(size));
+  main.mirroring_layer->SetTextureFlipped(flip_texture_);
 }
 
 void ReflectorImpl::FullRedrawOnMainThread(gfx::Size size) {
@@ -231,10 +234,14 @@ void ReflectorImpl::UpdateSubBufferOnMainThread(gfx::Size size,
   if (!main.mirroring_layer)
     return;
   UpdateTextureSizeOnMainThread(size);
-  // Flip the coordinates to compositor's one.
-  int y = size.height() - rect.y() - rect.height();
-  gfx::Rect new_rect(rect.x(), y, rect.width(), rect.height());
-  main.mirroring_layer->SchedulePaint(new_rect);
+  if(flip_texture_) {
+    // Flip the coordinates to compositor's one.
+    int y = size.height() - rect.y() - rect.height();
+    gfx::Rect new_rect(rect.x(), y, rect.width(), rect.height());
+    main.mirroring_layer->SchedulePaint(new_rect);
+  } else {
+    main.mirroring_layer->SchedulePaint(rect);

[danakj, 2015/01/12 18:27:30]

How about just doing rect math inside an if/else and keep the function call
outside, so there's only one?

[achaulk, 2015/01/12 18:47:35]

Sure

+  }
 }
 
 void ReflectorImpl::FullRedrawContentOnMainThread() {