viz: Wait for fullscreen damage after reallocating buffers

A page flip can result in a SWAP_NAK_RECREATE_BUFFERS signal,
indicating that the backing buffers must be recreated. Since the
buffers are entirely uninitialized, we should damage the entire
screen for the next draw [1].

Unfortunately, this doesn't work in SkiaRenderer because the GPU
thread performs the actual reallocation [2] and then posts a task to
the Viz thread to update the damage. The task taces with the next
invocation of DirectRenderer::DrawFrame, so there's no guarantee
that the new damage will be picked up in time for the next frame.
If it isn't, we will present a buffer with uninitialized data.

This CL fixes this issue by pausing SwapBuffer invocations after
reallocating buffers until we receive a frame with full screen
damage (e.g. the Viz thread catches up with the GPU thread).

[1] https://source.chromium.org/chromium/chromium/src/+/master:components/viz/service/display_embedder/gl_output_surface_buffer_queue.cc;l=263;drc=3c0194e7917daed5debe0d0772393e5784367e01
[2] https://source.chromium.org/chromium/chromium/src/+/master:components/viz/service/display_embedder/skia_output_device_buffer_queue.cc;l=458;drc=7ccffaf0933ccc647c744bf66971bcf5f33a676a

Bug: 1156182
Change-Id: Ibf0bf3d6903c4c4f2dadcfc71dfda36a03b513d3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2630227Reviewed-by: Vasiliy Telezhnikov <vasilyt@chromium.org>
Commit-Queue: Brian Ho <hob@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844167}

components/viz/service/display_embedder/skia_output_surface_impl.cc

@@ -901,6 +901,7 @@ void SkiaOutputSurfaceImpl::DidSwapBuffersComplete(
   // Reset |damage_of_buffers_|, if buffers are new created.
   if (params.swap_response.result ==
       gfx::SwapResult::SWAP_NAK_RECREATE_BUFFERS) {
+    client_->SetNeedsRedrawRect(gfx::Rect(size_));
     for (auto& damage : damage_of_buffers_)
       damage = gfx::Rect(size_);
   }

components/viz/service/display_embedder/skia_output_surface_impl_on_gpu.cc

@@ -1450,6 +1450,20 @@ void SkiaOutputSurfaceImplOnGpu::PostSubmit(
   scoped_output_device_paint_.reset();
 
   if (frame) {
+    if (waiting_for_full_damage_) {
+      // If we're using partial swap, we need to check whether the sub-buffer
+      // rect is actually the entire screen, but otherwise, the damage is
+      // always the full surface.
+      if (frame->sub_buffer_rect &&
+          capabilities().supports_post_sub_buffer &&
+          frame->sub_buffer_rect->size() != size_) {
+        output_surface_plane_.reset();
+        destroy_after_swap_.clear();
+        return;
+      }
+      waiting_for_full_damage_ = false;
+    }
+
     if (output_surface_plane_)
       DCHECK(output_device_->IsPrimaryPlaneOverlay());
     output_device_->SchedulePrimaryPlane(output_surface_plane_);
@@ -1540,6 +1554,16 @@ void SkiaOutputSurfaceImplOnGpu::DidSwapBuffersCompleteInternal(
       // Mark the context lost if not already lost.
       MarkContextLost(ContextLostReason::CONTEXT_LOST_SWAP_FAILED);
     }
+  } else if (params.swap_response.result ==
+             gfx::SwapResult::SWAP_NAK_RECREATE_BUFFERS) {
+    // We shouldn't present newly reallocated buffers until we have fully
+    // initialized their contents. SWAP_NAK_RECREAETE_BUFFERS should trigger a
+    // full-screen damage in DirectRenderer, but there is no guarantee that it
+    // will happen immediately since the SwapBuffersComplete task gets posted
+    // back to the Viz thread and will race with the next invocation of
+    // DrawFrame. To ensure we do not display uninitialized memory, we hold
+    // off on submitting new frames until we have received a full damage.
+    waiting_for_full_damage_ = true;
   }
 
 #if defined(OS_APPLE)

components/viz/service/display_embedder/skia_output_surface_impl_on_gpu.h

@@ -343,6 +343,8 @@ class SkiaOutputSurfaceImplOnGpu
   // Micro-optimization to get to issuing GPU SwapBuffers as soon as possible.
   std::vector<sk_sp<SkDeferredDisplayList>> destroy_after_swap_;
 
+  bool waiting_for_full_damage_ = false;
+
   int num_readbacks_pending_ = 0;
   bool readback_poll_pending_ = false;