Remove old Compositing.Surface* Histograms

Two old Histograms are coming up on expiry, and we haven't used them in
a long time. So I'm marking them Oboslete now:
  Compositing.SurfaceDependencyDeadline.Duration*
  Compositing.SurfaceManager.AliveSurfaces*

Bug: 1140020, 1140021
Change-Id: Ibbfd90c72edb2a206cf114b77682116061c613b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2505965Reviewed-by: kylechar <kylechar@chromium.org>
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Auto-Submit: Jonathan Ross <jonross@chromium.org>
Commit-Queue: Stephen Chenney <schenney@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822176}

components/viz/service/surfaces/surface_dependency_deadline.cc

@@ -4,7 +4,6 @@
 
 #include "components/viz/service/surfaces/surface_dependency_deadline.h"
 
-#include "base/metrics/histogram_macros.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/time/tick_clock.h"
 #include "components/viz/common/quads/frame_deadline.h"
@@ -38,12 +37,7 @@ base::Optional<base::TimeDelta> SurfaceDependencyDeadline::Cancel() {
 
   deadline_.reset();
 
-  base::TimeDelta duration = tick_clock_->NowTicks() - start_time_;
-
-  UMA_HISTOGRAM_TIMES("Compositing.SurfaceDependencyDeadline.Duration",
-                      duration);
-
-  return duration;
+  return tick_clock_->NowTicks() - start_time_;
 }
 
 bool SurfaceDependencyDeadline::operator==(

components/viz/service/surfaces/surface_manager.cc

@@ -13,7 +13,6 @@
 #include "base/containers/adapters.h"
 #include "base/containers/queue.h"
 #include "base/logging.h"
-#include "base/metrics/histogram_macros.h"
 #include "base/threading/sequenced_task_runner_handle.h"
 #include "base/time/default_tick_clock.h"
 #include "components/viz/common/surfaces/parent_local_surface_id_allocator.h"
@@ -30,8 +29,6 @@
 namespace viz {
 namespace {
 
-const char kUmaAliveSurfaces[] = "Compositing.SurfaceManager.AliveSurfaces";
-
 constexpr base::TimeDelta kExpireInterval = base::TimeDelta::FromSeconds(10);
 
 }  // namespace
@@ -185,11 +182,6 @@ void SurfaceManager::GarbageCollectSurfaces() {
   }
 
   SurfaceIdSet reachable_surfaces = GetLiveSurfaces();
-
-  // Log the number of reachable surfaces after a garbage collection.
-  UMA_HISTOGRAM_CUSTOM_COUNTS(kUmaAliveSurfaces, reachable_surfaces.size(), 1,
-                              200, 50);
-
   std::vector<SurfaceId> surfaces_to_delete;
 
   // Delete all destroyed and unreachable surfaces.

tools/metrics/histograms/histograms_xml/compositing/histograms.xml

@@ -587,6 +587,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="Compositing.SurfaceDependencyDeadline.Duration" units="ms"
     expires_after="2020-12-01">
+  <obsolete>
+    Expired October 2020.
+  </obsolete>
   <owner>jonross@chromium.org</owner>
   <owner>kylechar@chromium.org</owner>
   <summary>
@@ -598,6 +601,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="Compositing.SurfaceManager.AliveSurfaces" units="surfaces"
     expires_after="2020-12-01">
+  <obsolete>
+    Expired October 2020.
+  </obsolete>
   <owner>jonross@chromium.org</owner>
   <owner>kylechar@chromium.org</owner>
   <summary>