[Chromecast] Increase high buffer threshold to 1 second

Bug: internal b/117862002
Change-Id: Iae3c3ddd762bb8358e8a7b5bef68d5ba12743a67
Reviewed-on: https://chromium-review.googlesource.com/c/1318814Reviewed-by: Sergey Volk <servolk@chromium.org>
Commit-Queue: Kenneth MacKay <kmackay@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610932}

chromecast/media/cma/pipeline/media_pipeline_impl.cc

@@ -42,7 +42,7 @@ constexpr base::TimeDelta kHighBufferThresholdURL(
 constexpr base::TimeDelta kLowBufferThresholdMediaSource(
     base::TimeDelta::FromMilliseconds(0));
 constexpr base::TimeDelta kHighBufferThresholdMediaSource(
-    base::TimeDelta::FromMilliseconds(300));
+    base::TimeDelta::FromMilliseconds(1000));
 
 // Buffering parameters when load_type is kLoadTypeCommunication.
 constexpr base::TimeDelta kLowBufferThresholdCommunication(