[media] Lower log level for VTVDA initialization failure.

It is expected that initialization will fail when it is not supported by
the hardware, so lower these from DLOG(WARN) to DVLOG(1).

Failure to create a software decode session is still DLOG(WARN) because
this should work on all hardware.

Bug: 903656
Change-Id: I7bd62051c4c1d9082731b393d44166971f1aa0f6
Reviewed-on: https://chromium-review.googlesource.com/c/1334849Reviewed-by: Miguel Casas <mcasas@chromium.org>
Commit-Queue: Dan Sanders <sandersd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608078}

media/gpu/vt_video_decode_accelerator_mac.cc

@@ -190,7 +190,7 @@ bool CreateVideoToolboxSession(const uint8_t* sps,
       &callback,       // output_callback
       session.InitializeInto());
   if (status) {
-    OSSTATUS_DLOG(WARNING, status) << "Failed to create VTDecompressionSession";
+    OSSTATUS_DVLOG(1, status) << "Failed to create VTDecompressionSession";
     return false;
   }
 
@@ -212,7 +212,7 @@ bool InitializeVideoToolboxInternal() {
   const uint8_t pps_normal[] = {0x68, 0xe9, 0x7b, 0xcb};
   if (!CreateVideoToolboxSession(sps_normal, arraysize(sps_normal), pps_normal,
                                  arraysize(pps_normal), true)) {
-    DLOG(WARNING) << "Hardware decoding with VideoToolbox is not supported";
+    DVLOG(1) << "Hardware decoding with VideoToolbox is not supported";
     return false;
   }