Make DOMStorageContextWrapper a client of memory coordinator

content/browser/dom_storage/dom_storage_context_wrapper.cc

 // Copyright 2013 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 "content/browser/dom_storage/dom_storage_context_wrapper.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/files/file_path.h"
 #include "base/location.h"
+#include "base/memory/memory_coordinator_client_registry.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/filesystem/public/interfaces/directory.mojom.h"
 #include "components/leveldb/public/interfaces/leveldb.mojom.h"
 #include "content/browser/dom_storage/dom_storage_area.h"
 #include "content/browser/dom_storage/dom_storage_context_impl.h"
 #include "content/browser/dom_storage/dom_storage_task_runner.h"
 #include "content/browser/dom_storage/session_storage_namespace_impl.h"
 #include "content/browser/leveldb_wrapper_impl.h"
+#include "content/browser/memory/memory_coordinator.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/local_storage_usage_info.h"
 #include "content/public/browser/session_storage_usage_info.h"
 #include "mojo/common/common_type_converters.h"
 #include "services/file/public/cpp/constants.h"
 #include "services/file/public/interfaces/file_system.mojom.h"
 #include "services/shell/public/cpp/connection.h"
 #include "services/shell/public/cpp/connector.h"
 
 namespace content {
@@ skipping 241 matching lines @@
                         : data_path.AppendASCII(kLocalStorageDirectory),
       data_path.empty() ? data_path
                         : data_path.AppendASCII(kSessionStorageDirectory),
       special_storage_policy,
       new DOMStorageWorkerPoolTaskRunner(
           worker_pool,
           worker_pool->GetNamedSequenceToken("dom_storage_primary"),
           worker_pool->GetNamedSequenceToken("dom_storage_commit"),
           BrowserThread::GetTaskRunnerForThread(BrowserThread::IO).get()));
 
-  memory_pressure_listener_.reset(new base::MemoryPressureListener(
-      base::Bind(&DOMStorageContextWrapper::OnMemoryPressure, this)));
+  if (MemoryCoordinator::GetInstance()) {

[hajimehoshi, 2016/09/15 09:14:46]

bashi: Is this a correct usage to check whether MemoryCoordinator is enabled or
not?

+    base::MemoryCoordinatorClientRegistry::GetInstance()->Register(this);
+  } else {
+    memory_pressure_listener_.reset(new base::MemoryPressureListener(
+        base::Bind(&DOMStorageContextWrapper::OnMemoryPressure, this)));
+  }
 }
 
 DOMStorageContextWrapper::~DOMStorageContextWrapper() {}
 
 void DOMStorageContextWrapper::GetLocalStorageUsage(
     const GetLocalStorageUsageCallback& callback) {
   DCHECK(context_.get());
   context_->task_runner()->PostShutdownBlockingTask(
       FROM_HERE, DOMStorageTaskRunner::PRIMARY_SEQUENCE,
       base::Bind(&GetLocalStorageUsageHelper,
@@ skipping 59 matching lines @@
 }
 
 void DOMStorageContextWrapper::Shutdown() {
   DCHECK(context_.get());
   mojo_state_.reset();
   memory_pressure_listener_.reset();
   context_->task_runner()->PostShutdownBlockingTask(
       FROM_HERE,
       DOMStorageTaskRunner::PRIMARY_SEQUENCE,
       base::Bind(&DOMStorageContextImpl::Shutdown, context_));
+  if (MemoryCoordinator::GetInstance()) {
+    base::MemoryCoordinatorClientRegistry::GetInstance()->Unregister(this);
+  }
+
 }
 
 void DOMStorageContextWrapper::Flush() {
   DCHECK(context_.get());
   context_->task_runner()->PostShutdownBlockingTask(
       FROM_HERE, DOMStorageTaskRunner::PRIMARY_SEQUENCE,
       base::Bind(&DOMStorageContextImpl::Flush, context_));
 }
 
 void DOMStorageContextWrapper::OpenLocalStorage(
     const url::Origin& origin,
     mojom::LevelDBObserverPtr observer,
     mojom::LevelDBWrapperRequest request) {
   mojo_state_->OpenLocalStorage(
       origin, std::move(observer), std::move(request));
 }
 
 void DOMStorageContextWrapper::OnMemoryPressure(
     base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level) {
   DOMStorageContextImpl::PurgeOption purge_option =
       DOMStorageContextImpl::PURGE_UNOPENED;
   if (memory_pressure_level ==
       base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL) {
     purge_option = DOMStorageContextImpl::PURGE_AGGRESSIVE;
   }
+  PurgeMemory(purge_option);
+}
+
+void DOMStorageContextWrapper::OnMemoryStateChange(base::MemoryState state) {
+  // TODO(hajimehoshi): As OnMemoryStateChange changes the state, we should
+  // adjust the limitation to the amount of cache, DomStroageContextImpl doesn't
+  // have such limitation so far though.
+  switch (state) {
+    case base::MemoryState::NORMAL:
+      // Don't have to purge memory here.
+      break;
+    case base::MemoryState::THROTTLED:
+      // TOOD(hajimehoshi): We don't have throttling 'level' so far. When we
+      // have such value, let's change the argument accroding to the value.
+      PurgeMemory(DOMStorageContextImpl::PURGE_UNOPENED);
+      break;
+    case base::MemoryState::SUSPENDED:
+      // Note that SUSPENDED never occurs in the main browser process so far.
+      // Fall through.
+    case base::MemoryState::UNKNOWN:
+      NOTREACHED();
+      break;
+  }
+}
+
+void DOMStorageContextWrapper::PurgeMemory(DOMStorageContextImpl::PurgeOption
+    purge_option) {
   context_->task_runner()->PostTask(
       FROM_HERE,
       base::Bind(&DOMStorageContextImpl::PurgeMemory, context_, purge_option));
 }
 
 }  // namespace content