Remove the LowMemoryMargin field trial.

chrome/browser/chromeos/memory/oom_priority_manager.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/memory/oom_priority_manager.h"
 
 #include <algorithm>
 #include <set>
 #include <vector>
 
@@ skipping 39 matching lines @@
 using content::BrowserThread;
 using content::WebContents;
 
 namespace chromeos {
 
 namespace {
 
 // Name of the experiment to run.
 const char kExperiment[] = "LowMemoryMargin";
 
-#define EXPERIMENT_CUSTOM_COUNTS(name, sample, min, max, buckets)        \
-    {                                                                    \
-      UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, min, max, buckets);      \
-      if (base::FieldTrialList::TrialExists(kExperiment))                \
-        UMA_HISTOGRAM_CUSTOM_COUNTS(                                     \
-            base::FieldTrial::MakeName(name, kExperiment),               \
-            sample, min, max, buckets);                                  \
-    }
-
 // Record a size in megabytes, over a potential interval up to 32 GB.
-#define EXPERIMENT_HISTOGRAM_MEGABYTES(name, sample)                     \
-    EXPERIMENT_CUSTOM_COUNTS(name, sample, 1, 32768, 50)
+#define HISTOGRAM_MEGABYTES(name, sample)                     \
+    UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, 1, 32768, 50)
 
 // The default interval in seconds after which to adjust the oom_score_adj
 // value.
 const int kAdjustmentIntervalSeconds = 10;
 
 // For each period of this length we record a statistic to indicate whether
 // or not the user experienced a low memory event. If you change this interval
 // you must replace Tabs.Discard.DiscardInLastMinute with a new statistic.
 const int kRecentTabDiscardIntervalSeconds = 60;
 
@@ skipping 222 matching lines @@
     Browser* browser = *it;
     TabStripModel* model = browser->tab_strip_model();
     for (int idx = 0; idx < model->count(); idx++) {
       // Can't discard tabs that are already discarded or active.
       if (model->IsTabDiscarded(idx) || (model->active_index() == idx))
         continue;
       WebContents* web_contents = model->GetWebContentsAt(idx);
       int64 web_contents_id = IdFromWebContents(web_contents);
       if (web_contents_id == target_web_contents_id) {
         LOG(WARNING) << "Discarding tab " << idx
-            << " id " << target_web_contents_id;
+                     << " id " << target_web_contents_id;
         // Record statistics before discarding because we want to capture the
         // memory state that lead to the discard.
         RecordDiscardStatistics();
         model->DiscardWebContentsAt(idx);
         recent_tab_discard_ = true;
         return true;
       }
     }
   }
   return false;
 }
 
 void OomPriorityManager::RecordDiscardStatistics() {
   // Record a raw count so we can compare to discard reloads.
   discard_count_++;
-  EXPERIMENT_CUSTOM_COUNTS("Tabs.Discard.DiscardCount",
-                           discard_count_, 1, 1000, 50);
+  UMA_HISTOGRAM_CUSTOM_COUNTS(
+      "Tabs.Discard.DiscardCount", discard_count_, 1, 1000, 50);
 
   // TODO(jamescook): Maybe incorporate extension count?
-  EXPERIMENT_CUSTOM_COUNTS("Tabs.Discard.TabCount", GetTabCount(), 1, 100, 50);
+  UMA_HISTOGRAM_CUSTOM_COUNTS(
+      "Tabs.Discard.TabCount", GetTabCount(), 1, 100, 50);
 
   // TODO(jamescook): If the time stats prove too noisy, then divide up users
   // based on how heavily they use Chrome using tab count as a proxy.
   // Bin into <= 1, <= 2, <= 4, <= 8, etc.
   if (last_discard_time_.is_null()) {
     // This is the first discard this session.
     TimeDelta interval = TimeTicks::Now() - start_time_;
     int interval_seconds = static_cast<int>(interval.InSeconds());
     // Record time in seconds over an interval of approximately 1 day.
-    EXPERIMENT_CUSTOM_COUNTS(
+    UMA_HISTOGRAM_CUSTOM_COUNTS(
         "Tabs.Discard.InitialTime2", interval_seconds, 1, 100000, 50);
   } else {
     // Not the first discard, so compute time since last discard.
     TimeDelta interval = TimeTicks::Now() - last_discard_time_;
     int interval_ms = static_cast<int>(interval.InMilliseconds());
     // Record time in milliseconds over an interval of approximately 1 day.
     // Start at 100 ms to get extra resolution in the target 750 ms range.
-    EXPERIMENT_CUSTOM_COUNTS(
+    UMA_HISTOGRAM_CUSTOM_COUNTS(
         "Tabs.Discard.IntervalTime2", interval_ms, 100, 100000 * 1000, 50);
   }
   // Record Chrome's concept of system memory usage at the time of the discard.
   base::SystemMemoryInfoKB memory;
   if (base::GetSystemMemoryInfo(&memory)) {
     // TODO(jamescook): Remove this after R25 is deployed to stable. It does
     // not have sufficient resolution in the 2-4 GB range and does not properly
     // account for graphics memory on ARM. Replace with MemAllocatedMB below.
     int mem_anonymous_mb = (memory.active_anon + memory.inactive_anon) / 1024;
-    EXPERIMENT_HISTOGRAM_MEGABYTES("Tabs.Discard.MemAnonymousMB",
-                                   mem_anonymous_mb);
+    HISTOGRAM_MEGABYTES("Tabs.Discard.MemAnonymousMB", mem_anonymous_mb);
 
     // Record graphics GEM object size in a histogram with 50 MB buckets.
     int mem_graphics_gem_mb = 0;
     if (memory.gem_size != -1)
       mem_graphics_gem_mb = memory.gem_size / 1024 / 1024;
     RecordLinearHistogram(
         "Tabs.Discard.MemGraphicsMB", mem_graphics_gem_mb, 2500, 50);
 
     // Record shared memory (used by renderer/GPU buffers).
     int mem_shmem_mb = memory.shmem / 1024;
     RecordLinearHistogram("Tabs.Discard.MemShmemMB", mem_shmem_mb, 2500, 50);
 
     // On Intel, graphics objects are in anonymous pages, but on ARM they are
     // not. For a total "allocated count" add in graphics pages on ARM.
     int mem_allocated_mb = mem_anonymous_mb;
 #if defined(ARCH_CPU_ARM_FAMILY)
     mem_allocated_mb += mem_graphics_gem_mb;
 #endif
-    EXPERIMENT_CUSTOM_COUNTS("Tabs.Discard.MemAllocatedMB", mem_allocated_mb,
-                             256, 32768, 50)
+    UMA_HISTOGRAM_CUSTOM_COUNTS(
+        "Tabs.Discard.MemAllocatedMB", mem_allocated_mb, 256, 32768, 50);
 
     int mem_available_mb =
         (memory.active_file + memory.inactive_file + memory.free) / 1024;
-    EXPERIMENT_HISTOGRAM_MEGABYTES("Tabs.Discard.MemAvailableMB",
-                                   mem_available_mb);
+    HISTOGRAM_MEGABYTES("Tabs.Discard.MemAvailableMB", mem_available_mb);
   }
   // Set up to record the next interval.
   last_discard_time_ = TimeTicks::Now();
 }
 
 void OomPriorityManager::RecordRecentTabDiscard() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   // If we change the interval we need to change the histogram name.
   UMA_HISTOGRAM_BOOLEAN("Tabs.Discard.DiscardInLastMinute",
                         recent_tab_discard_);
@@ skipping 243 matching lines @@
         content::ZygoteHost::GetInstance()->AdjustRendererOOMScore(
             iterator->renderer_handle, score);
         pid_to_oom_score_[iterator->renderer_handle] = score;
       }
       priority += priority_increment;
     }
   }
 }
 
 }  // namespace chromeos