H265 VAAPI Accelerator

This adds the VAAPI accelerator delegate for H265 decoding. This is not
actually enabled yet because there are other pieces higher up in the
decoding pipeline that still need to be turned on.

BUG=chromium:1141237,b:153111783
TEST=HEVC playback works w/ full set of changes, vaapi_unittest

Change-Id: Ic0a2dbe774267d4852e0d4d47aa378c6602ad41f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2530798
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Sergey Volk <servolk@chromium.org>
Reviewed-by: Miguel Casas <mcasas@chromium.org>
Commit-Queue: Jeffrey Kardatzke <jkardatzke@google.com>
Cr-Commit-Position: refs/heads/master@{#827050}

media/gpu/h265_dpb.cc

@@ -16,6 +16,10 @@ H265Picture::~H265Picture() = default;
 H265DPB::H265DPB() = default;
 H265DPB::~H265DPB() = default;
 
+VaapiH265Picture* H265Picture::AsVaapiH265Picture() {
+  return nullptr;
+}
+
 void H265DPB::set_max_num_pics(size_t max_num_pics) {
   DCHECK_LE(max_num_pics, static_cast<size_t>(kMaxDpbSize));
   max_num_pics_ = max_num_pics;

media/gpu/h265_dpb.h

@@ -14,6 +14,8 @@
 
 namespace media {
 
+class VaapiH265Picture;
+
 // A picture (a frame or a field) in the H.265 spec sense.
 // See spec at http://www.itu.int/rec/T-REC-H.265
 class MEDIA_GPU_EXPORT H265Picture : public CodecPicture {
@@ -25,6 +27,8 @@ class MEDIA_GPU_EXPORT H265Picture : public CodecPicture {
   H265Picture(const H265Picture&) = delete;
   H265Picture& operator=(const H265Picture&) = delete;
 
+  virtual VaapiH265Picture* AsVaapiH265Picture();
+
   enum ReferenceType {
     kUnused = 0,
     kShortTermCurrBefore = 1,

media/gpu/vaapi/BUILD.gn

@@ -6,6 +6,7 @@ import("//build/config/chromeos/ui_mode.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//media/gpu/args.gni")
+import("//media/media_options.gni")
 import("//testing/test.gni")
 import("//tools/generate_stubs/rules.gni")
 import("//ui/gl/features.gni")
@@ -71,6 +72,12 @@ source_set("vaapi") {
     "vp9_vaapi_video_decoder_delegate.cc",
     "vp9_vaapi_video_decoder_delegate.h",
   ]
+  if (proprietary_codecs && enable_platform_hevc) {
+    sources += [
+      "h265_vaapi_video_decoder_delegate.cc",
+      "h265_vaapi_video_decoder_delegate.h",
+    ]
+  }
 
   configs += [
     "//build/config/linux/libva",
@@ -80,6 +87,7 @@ source_set("vaapi") {
   deps = [
     ":common",
     "//base",
+    "//build:chromeos_buildflags",
     "//gpu/config",
     "//gpu/ipc/common",
     "//gpu/ipc/service",