Explicitly set max_pending_frames = 1 for renderer output surfaces.

All configurations of CompositorOutputSurface have max_pending_frames
set to 1 but it's hard to see that unless you look at all of it's
subclasses. In particular both MailboxOutputSurface and
DelegatedCompositorOutputSurface set max_pending_frames to 1 and so does
the CompositorOutputSurface when using a SoftwareDevice. These are all
the configurations of CompositorOutputSurface that exist.

Review URL: https://codereview.chromium.org/1161283003

Cr-Commit-Position: refs/heads/master@{#333356}

5 files changed, 6 insertions, 6 deletions

diff --git a/content/renderer/gpu/compositor_output_surface.cc b/content/renderer/gpu/compositor_output_surface.cc
index 3695a18..c8270a6 100644
--- a/content/renderer/gpu/compositor_output_surface.cc
+++ b/content/renderer/gpu/compositor_output_surface.cc
@@ -60,10 +60,9 @@ CompositorOutputSurface::CompositorOutputSurface(
   DCHECK(output_surface_filter_.get());
   DCHECK(frame_swap_message_queue_.get());
   DetachFromThread();
+  capabilities_.max_frames_pending = 1;
   message_sender_ = RenderThreadImpl::current()->sync_message_filter();
   DCHECK(message_sender_.get());
-  if (OutputSurface::software_device())
-    capabilities_.max_frames_pending = 1;
 }
 
 CompositorOutputSurface::~CompositorOutputSurface() {
diff --git a/content/renderer/gpu/delegated_compositor_output_surface.cc b/content/renderer/gpu/delegated_compositor_output_surface.cc
index d767ce4..6d02fab 100644
--- a/content/renderer/gpu/delegated_compositor_output_surface.cc
+++ b/content/renderer/gpu/delegated_compositor_output_surface.cc
@@ -21,7 +21,6 @@ DelegatedCompositorOutputSurface::DelegatedCompositorOutputSurface(
                               swap_frame_message_queue,
                               true) {
   capabilities_.delegated_rendering = true;
-  capabilities_.max_frames_pending = 1;
 }
 
 }  // namespace content
diff --git a/content/renderer/gpu/mailbox_output_surface.cc b/content/renderer/gpu/mailbox_output_surface.cc
index dbf7acb..a715663 100644
--- a/content/renderer/gpu/mailbox_output_surface.cc
+++ b/content/renderer/gpu/mailbox_output_surface.cc
@@ -41,7 +41,6 @@ MailboxOutputSurface::MailboxOutputSurface(
       is_backbuffer_discarded_(false),
       format_(format) {
   pending_textures_.push_back(TransferableFrame());
-  capabilities_.max_frames_pending = 1;
   capabilities_.uses_default_gl_framebuffer = false;
 }
 
diff --git a/content/renderer/gpu/render_widget_compositor.cc b/content/renderer/gpu/render_widget_compositor.cc
index 99f2121..280b55e 100644
--- a/content/renderer/gpu/render_widget_compositor.cc
+++ b/content/renderer/gpu/render_widget_compositor.cc
@@ -904,6 +904,8 @@ void RenderWidgetCompositor::RequestNewOutputSurface() {
     return;
   }
 
+  DCHECK_EQ(surface->capabilities().max_frames_pending, 1);
+
   layer_tree_host_->SetOutputSurface(surface.Pass());
 }
 
diff --git a/content/renderer/gpu/render_widget_compositor_unittest.cc b/content/renderer/gpu/render_widget_compositor_unittest.cc
index 35774b7..b8ab096 100644
--- a/content/renderer/gpu/render_widget_compositor_unittest.cc
+++ b/content/renderer/gpu/render_widget_compositor_unittest.cc
@@ -142,11 +142,12 @@ class RenderWidgetCompositorOutputSurface : public RenderWidgetCompositor {
           cc::TestWebGraphicsContext3D::Create();
       // Image support required for synchronous compositing.
       context->set_support_image(true);
-      return cc::FakeOutputSurface::Create3d(context.Pass());
+      // Create delegating surface so that max_pending_frames = 1.
+      return cc::FakeOutputSurface::CreateDelegating3d(context.Pass());
     }
     return use_null_output_surface_
                ? nullptr
-               : make_scoped_ptr(new cc::FailureOutputSurface(false));
+               : make_scoped_ptr(new cc::FailureOutputSurface(true));
   }
 
   // Force a new output surface to be created.