Using base::Optional to avoid a pair of malloc and free for every frame.

Bug: None
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel
Change-Id: Ic881046b92c172d20d85db95b64799d38bd6d110
Reviewed-on: https://chromium-review.googlesource.com/1087682Reviewed-by: danakj <danakj@chromium.org>
Commit-Queue: Peng Huang <penghuang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#564873}

components/viz/service/display_embedder/skia_output_surface_impl.cc

@@ -139,7 +139,7 @@ SkiaOutputSurfaceImpl::SkiaOutputSurfaceImpl(
 
 SkiaOutputSurfaceImpl::~SkiaOutputSurfaceImpl() {
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
-  recorder_ = nullptr;
+  recorder_.reset();
   // Use GPU scheduler to release impl_on_gpu_ on the GPU thread, so all
   // scheduled tasks for the impl_on_gpu_ will be executed, before releasing
   // it. The GPU thread is the main thread of the viz process. It outlives the
@@ -197,7 +197,7 @@ void SkiaOutputSurfaceImpl::Reshape(const gfx::Size& size,
                                     bool use_stencil) {
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
 
-  recorder_ = nullptr;
+  recorder_.reset();
   SkSurfaceCharacterization* characterization = nullptr;
   std::unique_ptr<base::WaitableEvent> event;
   if (characterization_.isValid()) {
@@ -304,7 +304,7 @@ sk_sp<SkImage> SkiaOutputSurfaceImpl::MakePromiseSkImage(
   resource_sync_tokens_.push_back(metadata.sync_token);
 
   return PromiseTextureHelper<ResourceMetadata>::MakePromiseSkImage(
-      this, recorder_.get(), metadata.backend_format, metadata.size,
+      this, &recorder_.value(), metadata.backend_format, metadata.size,
       metadata.mip_mapped, metadata.origin, metadata.color_type,
       metadata.alpha_type, metadata.color_space, std::move(metadata));
 }
@@ -327,7 +327,7 @@ sk_sp<SkImage> SkiaOutputSurfaceImpl::MakePromiseSkImageFromYUV(
       gl::GetInternalFormat(version_info, GL_BGRA8_EXT), GL_TEXTURE_2D);
 
   return PromiseTextureHelper<YUVResourceMetadata>::MakePromiseSkImage(
-      this, recorder_.get(), backend_format, yuv_metadata.size(),
+      this, &recorder_.value(), backend_format, yuv_metadata.size(),
       GrMipMapped::kNo, kTopLeft_GrSurfaceOrigin, kBGRA_8888_SkColorType,
       kPremul_SkAlphaType, nullptr /* color_space */, std::move(yuv_metadata));
 }
@@ -392,8 +392,7 @@ SkCanvas* SkiaOutputSurfaceImpl::BeginPaintRenderPass(
       kCacheMaxResourceBytes, image_info, backend_format, msaa_sample_count,
       kTopLeft_GrSurfaceOrigin, surface_props, mipmap);
   DCHECK(characterization.isValid());
-  offscreen_surface_recorder_ =
-      std::make_unique<SkDeferredDisplayListRecorder>(characterization);
+  offscreen_surface_recorder_.emplace(characterization);
   return offscreen_surface_recorder_->getCanvas();
 }
 
@@ -409,7 +408,7 @@ gpu::SyncToken SkiaOutputSurfaceImpl::FinishPaintRenderPass() {
   sync_token.SetVerifyFlush();
 
   auto ddl = offscreen_surface_recorder_->detach();
-  offscreen_surface_recorder_ = nullptr;
+  offscreen_surface_recorder_.reset();
   DCHECK(ddl);
 
   auto sequence_id = gpu_service_->skia_output_surface_sequence_id();
@@ -442,7 +441,7 @@ sk_sp<SkImage> SkiaOutputSurfaceImpl::MakePromiseSkImageFromRenderPass(
   SkColorType color_type =
       ResourceFormatToClosestSkColorType(true /*gpu_compositing */, format);
   return PromiseTextureHelper<RenderPassId>::MakePromiseSkImage(
-      this, recorder_.get(), backend_format, size,
+      this, &recorder_.value(), backend_format, size,
       mipmap ? GrMipMapped::kYes : GrMipMapped::kNo, kTopLeft_GrSurfaceOrigin,
       color_type, kPremul_SkAlphaType, nullptr /* color_space */, id);
 }
@@ -479,8 +478,7 @@ void SkiaOutputSurfaceImpl::InitializeOnGpuThread(base::WaitableEvent* event) {
 void SkiaOutputSurfaceImpl::RecreateRecorder() {
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
   DCHECK(characterization_.isValid());
-  recorder_ =
-      std::make_unique<SkDeferredDisplayListRecorder>(characterization_);
+  recorder_.emplace(characterization_);
   // TODO(penghuang): remove the unnecessary getCanvas() call, when the
   // recorder crash is fixed in skia.
   recorder_->getCanvas();

components/viz/service/display_embedder/skia_output_surface_impl.h

@@ -6,6 +6,7 @@
 #define COMPONENTS_VIZ_SERVICE_DISPLAY_EMBEDDER_SKIA_OUTPUT_SURFACE_IMPL_H_
 
 #include "base/macros.h"
+#include "base/optional.h"
 #include "base/threading/thread_checker.h"
 #include "components/viz/service/display/skia_output_surface.h"
 #include "gpu/command_buffer/common/sync_token.h"
@@ -103,7 +104,7 @@ class SkiaOutputSurfaceImpl : public SkiaOutputSurface {
   OutputSurfaceClient* client_ = nullptr;
 
   SkSurfaceCharacterization characterization_;
-  std::unique_ptr<SkDeferredDisplayListRecorder> recorder_;
+  base::Optional<SkDeferredDisplayListRecorder> recorder_;
 
   // The current render pass id set by BeginPaintRenderPass.
   RenderPassId current_render_pass_id_ = 0;
@@ -111,7 +112,7 @@ class SkiaOutputSurfaceImpl : public SkiaOutputSurface {
   // The SkDDL recorder created by BeginPaintRenderPass, and
   // FinishPaintRenderPass will turn it into a SkDDL and play the SkDDL back on
   // the GPU thread.
-  std::unique_ptr<SkDeferredDisplayListRecorder> offscreen_surface_recorder_;
+  base::Optional<SkDeferredDisplayListRecorder> offscreen_surface_recorder_;
 
   // Sync tokens for resources which are used for the current frame.
   std::vector<gpu::SyncToken> resource_sync_tokens_;