Don't report VAAPI failures for UMA for platforms that don't support it.

On startup, VaapiWrapper::GetSupportedEncodeProfiles is
called to query HW encoder capabilities to fill GpuInfo
with. On VM test however there is no libva present, so we
error out, but also attempt to report an error to UMA,
which blocks and the GPU process gets killed by the GPU
watchdog.

We don't need to report failures on GetSupportedEncodeProfiles
however, as we will report them later when we attempt
to encode anyway.

BUG=402182
TEST=test lumpy under kvm and check chrome is not blocked by
GetSupportedEncodeProfiles
[email protected]

Review URL: https://codereview.chromium.org/613223002

Cr-Commit-Position: refs/heads/master@{#297564}
(cherry picked from commit 4505d0f)

Review URL: https://codereview.chromium.org/623613005

Cr-Commit-Position: refs/branch-heads/2171@{#25}
Cr-Branched-From: 267aeeb-refs/heads/master@{#297060}

content/common/gpu/media/vaapi_video_encode_accelerator.cc

@@ -114,7 +114,7 @@ VaapiVideoEncodeAccelerator::GetSupportedProfiles() {
 
   std::vector<media::VideoCodecProfile> hw_profiles =
       VaapiWrapper::GetSupportedEncodeProfiles(
-          x_display_, base::Bind(&ReportToUMA, VAAPI_ERROR));
+          x_display_, base::Bind(&base::DoNothing));
 
   media::VideoEncodeAccelerator::SupportedProfile profile;
   profile.max_resolution.SetSize(1920, 1088);