Disable reporting of global detached bytes

The global detached bytes include memory of unrelated frames and
extensions. We need to track per-frame detached bytes and only report
those in the same browsing context group.

Bug: 1085129
Change-Id: I3a562f0b3d898abe7508c46046cbd574db43173a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2628987Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843479}

third_party/blink/renderer/core/timing/measure_memory/measure_memory_controller.cc

@@ -210,10 +210,9 @@ MemoryMeasurement* ConvertResult(const WebMemoryMeasurementPtr& measurement) {
       breakdown.push_back(ConvertBreakdown(entry));
   }
   // Add breakdowns for memory that isn't attributed to an execution context.
-  breakdown.push_back(
-      CreateUnattributedBreakdown(measurement->detached_memory, "Detached"));
   breakdown.push_back(
       CreateUnattributedBreakdown(measurement->shared_memory, "Shared"));
+  // TODO(1085129): Report memory usage of detached frames once implemented.
   // Add an empty breakdown entry as required by the spec.
   // See https://github.com/WICG/performance-measure-memory/issues/10.
   breakdown.push_back(EmptyBreakdown());