media/gpu/vaapi: fix VA-API on X11 after Ozone was enabled

The CL "X11 and Ozone: enable use_x11 and use_ozone"
enabled both USE_OZONE and USE_X11 in the same build.
(https://crrev.com/c/2315869)

The feature IsUsingOzonePlatform() should be used to
check whether Ozone is actually in use or not. VA-API
support code did not do it properly, breaking VA-API
with X11. This patch fixes that.

Bug: 1129978

Change-Id: I64232207dd30b8a88bed7c250abc4ec2019210d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2418379
Commit-Queue: Tuukka Toivonen <tuukka.toivonen@intel.com>
Reviewed-by: Maksim Sisov (GMT+3) <msisov@igalia.com>
Reviewed-by: Ted Meyer <tmathmeyer@chromium.org>
Reviewed-by: Miguel Casas <mcasas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810139}

media/gpu/vaapi/vaapi_picture_factory.cc

@@ -82,18 +82,18 @@ VaapiPictureFactory::GetVaapiImplementation(gl::GLImplementation gl_impl) {
 
 uint32_t VaapiPictureFactory::GetGLTextureTarget() {
 #if defined(USE_OZONE)
-  return GL_TEXTURE_EXTERNAL_OES;
-#else
-  return GL_TEXTURE_2D;
+  if (features::IsUsingOzonePlatform())
+    return GL_TEXTURE_EXTERNAL_OES;
 #endif
+  return GL_TEXTURE_2D;
 }
 
 gfx::BufferFormat VaapiPictureFactory::GetBufferFormat() {
 #if defined(USE_OZONE)
-  return gfx::BufferFormat::YUV_420_BIPLANAR;
-#else
-  return gfx::BufferFormat::RGBX_8888;
+  if (features::IsUsingOzonePlatform())
+    return gfx::BufferFormat::YUV_420_BIPLANAR;
 #endif
+  return gfx::BufferFormat::RGBX_8888;
 }
 
 #if defined(USE_OZONE)