[ozone/wayland] Fix flickering problems with Weston.

The wl_surface_damage method was used in a wrong manner -
if a damage region is not supplied, the wl_surface_damage
still must be provided with the width and the height of the buffer
to update the surface with a new content.

This happens when partial swap is disabled and there is no damage
region provided.

What is more, instead of using wl_surface_damage, start using
wl_surface_damage_buffer, as long as the damage region corresponds
more to the buffer region contents rather than the surface itself
(and which is claimed to be a better approach by the Wayland
documentation)

Bug: 891188
Change-Id: Iff3a4eb50eae1a113818ef7881b6529b906f4820
Reviewed-on: https://chromium-review.googlesource.com/1255635Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
Commit-Queue: Maksim Sisov <msisov@igalia.com>
Cr-Commit-Position: refs/heads/master@{#595775}

ui/ozone/platform/wayland/wayland_buffer_manager.cc

@@ -44,8 +44,9 @@ base::TimeTicks GetPresentationFeedbackTimeStamp(uint32_t tv_sec_hi,
 
 WaylandBufferManager::Buffer::Buffer() = default;
 WaylandBufferManager::Buffer::Buffer(uint32_t id,
-                                     zwp_linux_buffer_params_v1* zwp_params)
-    : buffer_id(id), params(zwp_params) {}
+                                     zwp_linux_buffer_params_v1* zwp_params,
+                                     const gfx::Size& buffer_size)
+    : buffer_id(id), size(buffer_size), params(zwp_params) {}
 WaylandBufferManager::Buffer::~Buffer() = default;
 
 WaylandBufferManager::WaylandBufferManager(
@@ -97,7 +98,8 @@ bool WaylandBufferManager::CreateBuffer(base::File file,
   struct zwp_linux_buffer_params_v1* params =
       zwp_linux_dmabuf_v1_create_params(zwp_linux_dmabuf_.get());
 
-  std::unique_ptr<Buffer> buffer = std::make_unique<Buffer>(buffer_id, params);
+  std::unique_ptr<Buffer> buffer =
+      std::make_unique<Buffer>(buffer_id, params, gfx::Size(width, height));
   buffers_.insert(std::pair<uint32_t, std::unique_ptr<Buffer>>(
       buffer_id, std::move(buffer)));
 
@@ -188,9 +190,16 @@ bool WaylandBufferManager::SwapBuffer(Buffer* buffer) {
     return false;
   }
 
-  wl_surface_damage(window->surface(), buffer->damage_region.x(),
-                    buffer->damage_region.y(), buffer->damage_region.width(),
-                    buffer->damage_region.height());
+  gfx::Rect damage_region = buffer->damage_region;
+  // If the size of the damage region is empty, wl_surface_damage must be
+  // supplied with the actual size of the buffer, which is going to be
+  // committed.
+  if (damage_region.size().IsEmpty())
+    damage_region.set_size(buffer->size);
+
+  wl_surface_damage_buffer(window->surface(), damage_region.x(),
+                           damage_region.y(), damage_region.width(),
+                           damage_region.height());
   wl_surface_attach(window->surface(), buffer->wl_buffer.get(), 0, 0);
 
   static const wl_callback_listener frame_listener = {

ui/ozone/platform/wayland/wayland_buffer_manager.h

@@ -82,12 +82,17 @@ class WaylandBufferManager {
   // to this Buffer object on run-time.
   struct Buffer {
     Buffer();
-    Buffer(uint32_t id, zwp_linux_buffer_params_v1* zwp_params);
+    Buffer(uint32_t id,
+           zwp_linux_buffer_params_v1* zwp_params,
+           const gfx::Size& buffer_size);
     ~Buffer();
 
     // GPU GbmPixmapWayland corresponding buffer id.
     uint32_t buffer_id = 0;
 
+    // Actual buffer size.
+    const gfx::Size size;
+
     // Widget to attached/being attach WaylandWindow.
     gfx::AcceleratedWidget widget = gfx::kNullAcceleratedWidget;