base: removes base/allocator/allocator_extension

Looks it's dead code.

Bug: none
Change-Id: I41969fc9c9ef585cd2bcd3bd834567b52ce3a508
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5320270
Reviewed-by: Lei Zhang <thestig@chromium.org>
Owners-Override: Lei Zhang <thestig@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1264712}

base/BUILD.gn

@@ -215,8 +215,6 @@ component("base") {
   sources = [
     "allocator/allocator_check.cc",
     "allocator/allocator_check.h",
-    "allocator/allocator_extension.cc",
-    "allocator/allocator_extension.h",
     "allocator/dispatcher/configuration.h",
     "allocator/dispatcher/dispatcher.cc",
     "allocator/dispatcher/dispatcher.h",

base/allocator/README.md

@@ -35,8 +35,7 @@ indirectly, on `base` within the scope of a linker unit.
 More importantly, **no other place outside of `/base` should depend on the
 specific allocator**.
 If such a functional dependency is required that should be achieved using
-abstractions in `base` (see `/base/allocator/allocator_extension.h` and
-`/base/memory/`)
+abstractions in `base` (see `/base/memory/`)
 
 **Why `base` depends on `allocator`?**
 Because it needs to provide services that depend on the actual allocator

base/allocator/allocator_extension.cc

@@ -1,15 +0,0 @@
-// Copyright 2012 The Chromium Authors
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "base/allocator/allocator_extension.h"
-#include "base/allocator/buildflags.h"
-#include "base/check.h"
-
-namespace base {
-namespace allocator {
-
-void ReleaseFreeMemory() {}
-
-}  // namespace allocator
-}  // namespace base

base/allocator/allocator_extension.h

@@ -1,23 +0,0 @@
-// Copyright 2012 The Chromium Authors
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef BASE_ALLOCATOR_ALLOCATOR_EXTENSION_H_
-#define BASE_ALLOCATOR_ALLOCATOR_EXTENSION_H_
-
-#include <stddef.h>  // for size_t
-
-#include "base/base_export.h"
-#include "build/build_config.h"
-
-namespace base {
-namespace allocator {
-
-// Request that the allocator release any free memory it knows about to the
-// system.
-BASE_EXPORT void ReleaseFreeMemory();
-
-}  // namespace allocator
-}  // namespace base
-
-#endif  // BASE_ALLOCATOR_ALLOCATOR_EXTENSION_H_

base/trace_event/malloc_dump_provider.cc

@@ -8,7 +8,6 @@
 
 #include <unordered_map>
 
-#include "base/allocator/allocator_extension.h"
 #include "base/allocator/buildflags.h"
 #include "base/allocator/partition_allocator/src/partition_alloc/partition_alloc_buildflags.h"
 #include "base/allocator/partition_allocator/src/partition_alloc/partition_alloc_config.h"

build/android/gyp/extract_unwind_tables_tests.py

@@ -29,8 +29,7 @@ class TestExtractUnwindTables(unittest.TestCase):
 MODULE Linux arm CDE12FE1DF2B37A9C6560B4CBEE056420 lib_chrome.so
 INFO CODE_ID E12FE1CD2BDFA937C6560B4CBEE05642
 FILE 0 ../../base/allocator/allocator_check.cc
-FILE 1 ../../base/allocator/allocator_extension.cc
-FILE 2 ../../base/allocator/allocator_shim.cc
+FILE 1 ../../base/allocator/allocator_shim.cc
 FUNC 1adcb60 54 0 i2d_name_canon
 1adcb60 1a 509 17054
 3b94c70 2 69 40

content/browser/zygote_host/zygote_host_impl_linux.cc

@@ -8,7 +8,6 @@
 #include <sys/socket.h>
 #include <sys/types.h>
 
-#include "base/allocator/allocator_extension.h"
 #include "base/files/file_enumerator.h"
 #include "base/logging.h"
 #include "base/posix/unix_domain_socket.h"

content/gpu/gpu_child_thread.cc

@@ -9,7 +9,6 @@
 #include <memory>
 #include <utility>
 
-#include "base/allocator/allocator_extension.h"
 #include "base/command_line.h"
 #include "base/debug/dump_without_crashing.h"
 #include "base/functional/bind.h"
@@ -239,7 +238,6 @@ void GpuChildThread::OnMemoryPressure(
   if (level != base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL)
     return;
 
-  base::allocator::ReleaseFreeMemory();
   if (viz_main_.discardable_shared_memory_manager())
     viz_main_.discardable_shared_memory_manager()->ReleaseFreeMemory();
   SkGraphics::PurgeAllCaches();

content/renderer/render_thread_impl.cc

@@ -11,7 +11,6 @@
 #include <utility>
 #include <vector>
 
-#include "base/allocator/allocator_extension.h"
 #include "base/allocator/partition_alloc_support.h"
 #include "base/at_exit.h"
 #include "base/command_line.h"
@@ -1685,7 +1684,6 @@ void RenderThreadImpl::OnRendererForegrounded() {
 
 void RenderThreadImpl::ReleaseFreeMemory() {
   TRACE_EVENT0("blink", "RenderThreadImpl::ReleaseFreeMemory()");
-  base::allocator::ReleaseFreeMemory();
   discardable_memory_allocator_->ReleaseFreeMemory();
 
   // Do not call into blink if it is not initialized.