IndexedDB: Remove WebCore.IndexedDB.FrontEndAPICalls UMA histogram.

The metrics have not been used in a while, and have no immediately clear
use case.

Bug: 850539
Change-Id: If11dcadf946bc66071ecb85aa126981a149193b3
Reviewed-on: https://chromium-review.googlesource.com/1146076Reviewed-by: Mark Pearson <mpearson@chromium.org>
Reviewed-by: Daniel Murphy <dmurph@chromium.org>
Commit-Queue: Daniel Murphy <dmurph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577249}

third_party/blink/renderer/modules/indexeddb/BUILD.gn

@@ -22,7 +22,6 @@ blink_modules_sources("indexeddb") {
     "idb_event_dispatcher.h",
     "idb_factory.cc",
     "idb_factory.h",
-    "idb_histograms.h",
     "idb_index.cc",
     "idb_index.h",
     "idb_key.cc",

third_party/blink/renderer/modules/indexeddb/idb_database.cc

@@ -265,7 +265,6 @@ IDBObjectStore* IDBDatabase::createObjectStore(
     bool auto_increment,
     ExceptionState& exception_state) {
   IDB_TRACE("IDBDatabase::createObjectStore");
-  RecordApiCallsHistogram(kIDBCreateObjectStoreCall);
 
   if (!version_change_transaction_) {
     exception_state.ThrowDOMException(
@@ -331,7 +330,6 @@ IDBObjectStore* IDBDatabase::createObjectStore(
 void IDBDatabase::deleteObjectStore(const String& name,
                                     ExceptionState& exception_state) {
   IDB_TRACE("IDBDatabase::deleteObjectStore");
-  RecordApiCallsHistogram(kIDBDeleteObjectStoreCall);
   if (!version_change_transaction_) {
     exception_state.ThrowDOMException(
         DOMExceptionCode::kInvalidStateError,
@@ -371,7 +369,6 @@ IDBTransaction* IDBDatabase::transaction(
     const String& mode_string,
     ExceptionState& exception_state) {
   IDB_TRACE("IDBDatabase::transaction");
-  RecordApiCallsHistogram(kIDBTransactionCall);
 
   HashSet<String> scope;
   if (store_names.IsString()) {
@@ -598,13 +595,6 @@ ExecutionContext* IDBDatabase::GetExecutionContext() const {
   return ContextLifecycleObserver::GetExecutionContext();
 }
 
-void IDBDatabase::RecordApiCallsHistogram(IndexedDatabaseMethods method) {
-  DEFINE_THREAD_SAFE_STATIC_LOCAL(
-      EnumerationHistogram, api_calls_histogram,
-      ("WebCore.IndexedDB.FrontEndAPICalls", kIDBMethodsMax));
-  api_calls_histogram.Count(method);
-}
-
 STATIC_ASSERT_ENUM(kWebIDBDatabaseExceptionUnknownError,
                    DOMExceptionCode::kUnknownError);
 STATIC_ASSERT_ENUM(kWebIDBDatabaseExceptionConstraintError,

third_party/blink/renderer/modules/indexeddb/idb_database.h

@@ -38,7 +38,6 @@
 #include "third_party/blink/renderer/modules/event_modules.h"
 #include "third_party/blink/renderer/modules/event_target_modules.h"
 #include "third_party/blink/renderer/modules/indexeddb/idb_database_callbacks.h"
-#include "third_party/blink/renderer/modules/indexeddb/idb_histograms.h"
 #include "third_party/blink/renderer/modules/indexeddb/idb_metadata.h"
 #include "third_party/blink/renderer/modules/indexeddb/idb_object_store.h"
 #include "third_party/blink/renderer/modules/indexeddb/idb_object_store_parameters.h"
@@ -171,8 +170,6 @@ class MODULES_EXPORT IDBDatabase final
   static const char kTransactionReadOnlyErrorMessage[];
   static const char kDatabaseClosedErrorMessage[];
 
-  static void RecordApiCallsHistogram(IndexedDatabaseMethods);
-
  protected:
   // EventTarget
   DispatchEventResult DispatchEventInternal(Event*) override;

third_party/blink/renderer/modules/indexeddb/idb_factory.cc

@@ -120,7 +120,6 @@ IDBOpenDBRequest* IDBFactory::OpenInternal(ScriptState* script_state,
                                            ExceptionState& exception_state) {
   IDB_TRACE1("IDBFactory::open", "name", name.Utf8());
   IDBRequest::AsyncTraceState metrics("IDBFactory::open");
-  IDBDatabase::RecordApiCallsHistogram(kIDBOpenCall);
   DCHECK(version >= 1 || version == IDBDatabaseMetadata::kNoVersion);
   if (!IsContextValid(ExecutionContext::From(script_state)))
     return nullptr;
@@ -190,7 +189,6 @@ IDBOpenDBRequest* IDBFactory::DeleteDatabaseInternal(
     bool force_close) {
   IDB_TRACE1("IDBFactory::deleteDatabase", "name", name.Utf8());
   IDBRequest::AsyncTraceState metrics("IDBFactory::deleteDatabase");
-  IDBDatabase::RecordApiCallsHistogram(kIDBDeleteDatabaseCall);
   if (!IsContextValid(ExecutionContext::From(script_state)))
     return nullptr;
   if (!ExecutionContext::From(script_state)

third_party/blink/renderer/modules/indexeddb/idb_histograms.h

-/*
- * Copyright (C) 2013 Google Inc. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1.  Redistributions of source code must retain the above copyright
- *     notice, this list of conditions and the following disclaimer.
- * 2.  Redistributions in binary form must reproduce the above copyright
- *     notice, this list of conditions and the following disclaimer in the
- *     documentation and/or other materials provided with the distribution.
- * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
- *     its contributors may be used to endorse or promote products derived
- *     from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY GOOGLE AND ITS CONTRIBUTORS "AS IS" AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
- * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_INDEXEDDB_IDB_HISTOGRAMS_H_
-#define THIRD_PARTY_BLINK_RENDERER_MODULES_INDEXEDDB_IDB_HISTOGRAMS_H_
-
-namespace blink {
-
-enum IndexedDatabaseMethods {
-  kIDBCreateObjectStoreCall,
-  kIDBDeleteObjectStoreCall,
-  kIDBTransactionCall,
-  kIDBDeleteDatabaseCall,
-  kIDBOpenCall,
-  kIDBMethodsMax,
-};
-
-}  // namespace blink
-
-#endif

tools/metrics/histograms/enums.xml

@@ -24368,6 +24368,9 @@ Called by update_gpu_driver_bug_workaround_entries.py.-->
 </enum>
 
 <enum name="IndexedDatabaseMethods">
+  <obsolete>
+    Deprecated as of July 2018.
+  </obsolete>
   <int value="0" label="CreateObjectStore()"/>
   <int value="1" label="DeleteObjectStore()"/>
   <int value="2" label="Transaction()"/>

tools/metrics/histograms/histograms.xml

@@ -110275,6 +110275,9 @@ uploading your change for review.
 
 <histogram name="WebCore.IndexedDB.FrontEndAPICalls"
     enum="IndexedDatabaseMethods">
+  <obsolete>
+    Deprecated as of July 2018.
+  </obsolete>
   <owner>dgrogan@chromium.org</owner>
   <summary>
     Count total number of front end API calls of IndexedDB methods.