Remove deprecated storage histograms.

LevelDBEnv.IDB.LockFileAncestorsNotFound
LevelDBEnv.ServiceWorker.LockFileAncestorsNotFound
LevelDBEnv.LockFileAncestorsNotFound

Bug: 969973
Change-Id: Ie8f55d5ad09fe00e63e95681c2781283a822281c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1663036Reviewed-by: Victor Costan <pwnall@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Commit-Queue: David Grogan <dgrogan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#669894}

third_party/leveldatabase/env_chromium.cc

@@ -994,22 +994,8 @@ Status ChromiumEnv::LockFile(const std::string& fname, FileLock** lock) {
   } while (!file.IsValid() && retrier.ShouldKeepTrying(error_code));
 
   if (!file.IsValid()) {
-    if (error_code == base::File::FILE_ERROR_NOT_FOUND) {
-      FilePath parent = FilePath::FromUTF8Unsafe(fname).DirName();
-      FilePath last_parent;
-      int num_missing_ancestors = 0;
-      do {
-        if (base::DirectoryExists(parent))
-          break;
-        ++num_missing_ancestors;
-        last_parent = parent;
-        parent = parent.DirName();
-      } while (parent != last_parent);
-      RecordLockFileAncestors(num_missing_ancestors);
-    }
-
-    result = MakeIOError(fname, FileErrorString(error_code), kLockFile,
-                         error_code);
+    result =
+        MakeIOError(fname, FileErrorString(error_code), kLockFile, error_code);
     RecordOSError(kLockFile, error_code);
     return result;
   }
@@ -1183,10 +1169,6 @@ void ChromiumEnv::RecordBytesWritten(int amount) const {
   RecordStorageBytesWritten(name_.c_str(), amount);
 }
 
-void ChromiumEnv::RecordLockFileAncestors(int num_missing_ancestors) const {
-  GetLockFileAncestorHistogram()->Add(num_missing_ancestors);
-}
-
 base::HistogramBase* ChromiumEnv::GetOSErrorHistogram(MethodID method,
                                                       int limit) const {
   std::string uma_name;
@@ -1203,17 +1185,6 @@ base::HistogramBase* ChromiumEnv::GetMethodIOErrorHistogram() const {
       kNumEntries + 1, base::Histogram::kUmaTargetedHistogramFlag);
 }
 
-base::HistogramBase* ChromiumEnv::GetLockFileAncestorHistogram() const {
-  std::string uma_name(name_);
-  uma_name.append(".LockFileAncestorsNotFound");
-  const int kMin = 1;
-  const int kMax = 10;
-  const int kNumBuckets = 11;
-  return base::LinearHistogram::FactoryGet(
-      uma_name, kMin, kMax, kNumBuckets,
-      base::Histogram::kUmaTargetedHistogramFlag);
-}
-
 base::HistogramBase* ChromiumEnv::GetRetryTimeHistogram(MethodID method) const {
   std::string uma_name(name_);
   // TODO(dgrogan): This is probably not the best way to concatenate strings.

third_party/leveldatabase/env_chromium.h

@@ -225,9 +225,7 @@ class LEVELDB_EXPORT ChromiumEnv : public leveldb::Env,
     reinterpret_cast<ChromiumEnv*>(arg)->BGThread();
   }
 
-  void RecordLockFileAncestors(int num_missing_ancestors) const;
   base::HistogramBase* GetMethodIOErrorHistogram() const;
-  base::HistogramBase* GetLockFileAncestorHistogram() const;
 
   // RetrierProvider implementation.
   int MaxRetryTimeMillis() const override { return kMaxRetryTimeMillis; }

tools/metrics/histograms/histograms.xml

@@ -51635,6 +51635,9 @@ uploading your change for review.
 
 <histogram name="LevelDBEnv.LockFileAncestorsNotFound" units="directories"
     expires_after="M77">
+  <obsolete>
+    Deprecated 2019-06.
+  </obsolete>
   <owner>dgrogan@chromium.org</owner>
   <summary>
     Number of directories missing when Non-IDB LevelDBEnv tries to create a Lock