Stop emitting "resident_set_bytes" in memory-infra traces.

Now that we emit private memory footprint, the former number is not
particularly meaningful.

Bug: 815328
Change-Id: I85cb76b08ef85073179b5c334c16d4775667b8e6
Reviewed-on: https://chromium-review.googlesource.com/940144
Commit-Queue: Erik Chen <erikchen@chromium.org>
Reviewed-by: Primiano Tucci <primiano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#540197}

services/resource_coordinator/public/cpp/memory_instrumentation/tracing_observer.cc

@@ -29,10 +29,6 @@ bool IsMemoryInfraTracingEnabled() {
 }
 
 void OsDumpAsValueInto(TracedValue* value, const mojom::OSMemDump& os_dump) {
-  value->SetString(
-      "resident_set_bytes",
-      base::StringPrintf(
-          "%" PRIx64, static_cast<uint64_t>(os_dump.resident_set_kb) * 1024));
   value->SetString(
       "private_footprint_bytes",
       base::StringPrintf(