Update to latest trace-viewer (a7f1c1b3)

Includes rewrite of prefix.html to switch from TraceViewer
to timeline-view, and account for new location of the
vulcanizer.

Cherry-pick of ced05db70069f9d84c4b0dd9b3b26b94e3482336 from AOSP

Change-Id: I07285c64bde7d4bfe414c9e93b097435e118a069
diff --git a/trace-viewer/codereview.settings b/trace-viewer/codereview.settings
index c17614f..7e92d93 100644
--- a/trace-viewer/codereview.settings
+++ b/trace-viewer/codereview.settings
@@ -1,5 +1,5 @@
 # This file is used by gcl to get repository specific information.
 CODE_REVIEW_SERVER: codereview.appspot.com
-CC_LIST: trace-viewer-review@googlegroups.com
+CC_LIST: tracing-review@chromium.org
 VIEW_VC: https://chromium.googlesource.com/external/trace-viewer/+/
 PROJECT: trace-viewer