vulkan: fix a crash in SkiaOutputDeviceVulkan.

The crash is because we assume vulkan driver will always create
swapchain with the number of images which is specified by
VkSwapchainCreateInfoKHR::minImageCount, but sometimes, the driver
will not obey it, and then it causes problems. fix the crash by using
the number from the swapchain instead of assuming it.

Bug: 1099132
Change-Id: I70868d1bf9efee4d845ff21a236af33eac401ad5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2281177
Commit-Queue: Vasiliy Telezhnikov <vasilyt@chromium.org>
Auto-Submit: Peng Huang <penghuang@chromium.org>
Reviewed-by: Vasiliy Telezhnikov <vasilyt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#785357}

components/viz/service/display_embedder/skia_output_device_vulkan.cc

@@ -271,7 +271,6 @@ bool SkiaOutputDeviceVulkan::Initialize() {
 
   capabilities_.uses_default_gl_framebuffer = false;
   capabilities_.max_frames_pending = 1;
-  capabilities_.number_of_buffers = vulkan_surface_->image_count();
   // Vulkan FIFO swap chain should return vk images in presenting order, so set
   // preserve_buffer_content & supports_post_sub_buffer to true to let
   // SkiaOutputBufferImpl to manager damages.
@@ -279,6 +278,11 @@ bool SkiaOutputDeviceVulkan::Initialize() {
   capabilities_.output_surface_origin = gfx::SurfaceOrigin::kTopLeft;
   capabilities_.supports_post_sub_buffer = true;
   capabilities_.supports_pre_transform = true;
+  // We don't know the number of buffers until the VulkanSwapChain is
+  // initialized, so set it to 0. Since |damage_area_from_skia_output_device| is
+  // assigned to true, so |number_of_buffers| will not be used for tracking
+  // framebuffer damages.
+  capabilities_.number_of_buffers = 0;
   capabilities_.damage_area_from_skia_output_device = true;
 
   const auto surface_format = vulkan_surface_->surface_format().format;
@@ -308,10 +312,11 @@ bool SkiaOutputDeviceVulkan::RecreateSwapChain(
     for (const auto& sk_surface_size_pair : sk_surface_size_pairs_) {
       memory_type_tracker_->TrackMemFree(sk_surface_size_pair.bytes_allocated);
     }
+    auto num_images = vulkan_surface_->swap_chain()->num_images();
     sk_surface_size_pairs_.clear();
-    sk_surface_size_pairs_.resize(vulkan_surface_->swap_chain()->num_images());
+    sk_surface_size_pairs_.resize(num_images);
     color_space_ = std::move(color_space);
-    damage_of_images_.resize(vulkan_surface_->image_count());
+    damage_of_images_.resize(num_images);
     for (auto& damage : damage_of_images_)
       damage = gfx::Rect(vulkan_surface_->image_size());
     is_new_swap_chain_ = true;

gpu/vulkan/vulkan_surface.cc

@@ -170,8 +170,6 @@ bool VulkanSurface::Initialize(VulkanDeviceQueue* device_queue,
     return false;
   }
 
-  image_count_ = std::max(surface_caps.minImageCount, kMinImageCount);
-
   constexpr auto kRequiredUsageFlags =
       VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
   if ((surface_caps.supportedUsageFlags & kRequiredUsageFlags) !=
@@ -283,11 +281,10 @@ bool VulkanSurface::CreateSwapChain(const gfx::Size& size,
   transform_ = transform;
 
   auto swap_chain = std::make_unique<VulkanSwapChain>();
-
   // Create swap chain.
-  DCHECK_EQ(image_count_, std::max(surface_caps.minImageCount, kMinImageCount));
+  auto min_image_count = std::max(surface_caps.minImageCount, kMinImageCount);
   if (!swap_chain->Initialize(device_queue_, surface_, surface_format_,
-                              image_size_, image_count_, image_usage_flags_,
+                              image_size_, min_image_count, image_usage_flags_,
                               vk_transform, enforce_protected_memory_,
                               std::move(swap_chain_))) {
     return false;

gpu/vulkan/vulkan_surface.h

@@ -66,7 +66,6 @@ class COMPONENT_EXPORT(VULKAN) VulkanSurface {
   const gfx::Size& image_size() const { return image_size_; }
   VkImageUsageFlags image_usage_flags() const { return image_usage_flags_; }
   gfx::OverlayTransform transform() const { return transform_; }
-  uint32_t image_count() const { return image_count_; }
   VkSurfaceFormatKHR surface_format() const { return surface_format_; }
 
  private:
@@ -93,9 +92,6 @@ class COMPONENT_EXPORT(VULKAN) VulkanSurface {
   // Swap chain pre-transform.
   gfx::OverlayTransform transform_ = gfx::OVERLAY_TRANSFORM_INVALID;
 
-  // Swap chain image count.
-  uint32_t image_count_ = 0u;
-
   std::unique_ptr<VulkanSwapChain> swap_chain_;
 
   DISALLOW_COPY_AND_ASSIGN(VulkanSurface);