ui: utilise segment forest to improve slice tracks on large traces

This CL introduces the use of the segment forest to significantly speed
up the queries of slice tracks on large traces. Specifically the data
structure is exposed to Typescript via the use of a new "SliceMipmap"
trace processor operator.

This CL only ports base_slice_track to the operator: other tracks will
be ported in followup CLs.

Change-Id: Icf5d5a620b01dece7b102f9bdae181db0ee145fc

1 files changed, 8 insertions, 8 deletions

diff --git a/ui/src/frontend/base_slice_track_unittest.ts b/ui/src/frontend/base_slice_track_unittest.ts
index 196cc2ea5..4e8fd5182 100644
--- a/ui/src/frontend/base_slice_track_unittest.ts
+++ b/ui/src/frontend/base_slice_track_unittest.ts
@@ -19,16 +19,16 @@ import {Slice} from '../public';
 import {filterVisibleSlicesForTesting as filterVisibleSlices} from './base_slice_track';
 
 function slice(start: number, duration: number, depth: number = 0): Slice {
-  const startNsQ = Time.fromRaw(BigInt(start));
-  const durNsQ = Time.fromRaw(BigInt(duration));
-  const endNsQ = Time.fromRaw(startNsQ + durNsQ);
+  const startNs = Time.fromRaw(BigInt(start));
+  const durNs = Time.fromRaw(BigInt(duration));
+  const endNs = Time.fromRaw(startNs + durNs);
   return {
     id: 42,
-    startNsQ,
-    endNsQ,
-    durNsQ,
-    ts: startNsQ,
-    dur: durNsQ,
+    startNs,
+    endNs,
+    durNs,
+    ts: startNs,
+    dur: durNs,
     depth,
     flags: 0,
     title: '',