Add a feature flag for VA-API VP8 video encoder.

Add a feature flag to enable VA-API-based VP8 hardware video encode
acceleration.

BUG=794608
TEST=run Chrome with feature disabled/enabled, verify availability

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: I5866d7b158a071ea94b06d49453af1ec85ba3e2e
Reviewed-on: https://chromium-review.googlesource.com/1068905Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Pawel Osciak <posciak@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561303}

media/base/media_switches.cc

@@ -305,6 +305,10 @@ const base::Feature kUnifiedAutoplay{"UnifiedAutoplay",
 const base::Feature kUseSurfaceLayerForVideo{"UseSurfaceLayerForVideo",
                                              base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Enable VA-API hardware encode acceleration for VP8.
+const base::Feature kVaapiVP8Encoder{"VaapiVP8Encoder",
+                                     base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Inform video blitter of video color space.
 const base::Feature kVideoBlitColorAccuracy{"video-blit-color-accuracy",
                                             base::FEATURE_ENABLED_BY_DEFAULT};

media/base/media_switches.h

@@ -131,6 +131,7 @@ MEDIA_EXPORT extern const base::Feature kUseAndroidOverlay;
 MEDIA_EXPORT extern const base::Feature kUseAndroidOverlayAggressively;
 MEDIA_EXPORT extern const base::Feature kUseNewMediaCache;
 MEDIA_EXPORT extern const base::Feature kUseR16Texture;
+MEDIA_EXPORT extern const base::Feature kVaapiVP8Encoder;
 MEDIA_EXPORT extern const base::Feature kVideoBlitColorAccuracy;
 MEDIA_EXPORT extern const base::Feature kUnifiedAutoplay;
 MEDIA_EXPORT extern const base::Feature kUseSurfaceLayerForVideo;

media/gpu/vaapi/vaapi_wrapper.cc

@@ -24,6 +24,8 @@
 #include "base/sys_info.h"
 #include "build/build_config.h"
 
+#include "media/base/media_switches.h"
+
 // Auto-generated for dlopen libva libraries
 #include "media/gpu/vaapi/va_stubs.h"
 
@@ -176,6 +178,14 @@ bool IsBlackListedDriver(const std::string& va_vendor_string,
       return true;
     }
   }
+
+  // TODO(posciak): Remove once VP8 encoding is to be enabled by default.
+  if (mode == VaapiWrapper::CodecMode::kEncode &&
+      va_profile == VAProfileVP8Version0_3 &&
+      !base::FeatureList::IsEnabled(kVaapiVP8Encoder)) {
+    return true;
+  }
+
   return false;
 }