gpu:: Remove GpuDataManagerObserver::OnVideoMemoryUsageStatsUpdate().

chrome/browser/task_manager/sampling/task_manager_impl.cc

 // Copyright 2015 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/task_manager/sampling/task_manager_impl.h"
 
 #include <algorithm>
 #include <string>
 #include <unordered_map>
 #include <unordered_set>
@@ skipping 32 matching lines @@
     lazy_task_manager_instance = LAZY_INSTANCE_INITIALIZER;
 
 }  // namespace
 
 TaskManagerImpl::TaskManagerImpl()
     : on_background_data_ready_callback_(
           base::Bind(&TaskManagerImpl::OnTaskGroupBackgroundCalculationsDone,
                      base::Unretained(this))),
       blocking_pool_runner_(GetBlockingPoolRunner()),
       shared_sampler_(new SharedSampler(blocking_pool_runner_)),
-      is_running_(false) {
+      is_running_(false),
+      weak_ptr_factory_(this) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   task_providers_.emplace_back(new BrowserProcessTaskProvider());
   task_providers_.emplace_back(new ChildProcessTaskProvider());
   task_providers_.emplace_back(new WebContentsTaskProvider());
 #if defined(OS_CHROMEOS)
   if (arc::IsArcAvailable())
     task_providers_.emplace_back(new ArcProcessTaskProvider());
 #endif  // defined(OS_CHROMEOS)
-
-  content::GpuDataManager::GetInstance()->AddObserver(this);
 }
 
 TaskManagerImpl::~TaskManagerImpl() {
-  content::GpuDataManager::GetInstance()->RemoveObserver(this);
 }
 
 // static
 TaskManagerImpl* TaskManagerImpl::GetInstance() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   return lazy_task_manager_instance.Pointer();
 }
 
 void TaskManagerImpl::ActivateTask(TaskId task_id) {
@@ skipping 366 matching lines @@
 
   // Invalidate the cached sorted IDs by clearing the list.
   sorted_task_ids_.clear();
 }
 
 void TaskManagerImpl::TaskUnresponsive(Task* task) {
   DCHECK(task);
   NotifyObserversOnTaskUnresponsive(task->task_id());
 }
 
-void TaskManagerImpl::OnVideoMemoryUsageStatsUpdate(
-    const gpu::VideoMemoryUsageStats& gpu_memory_stats) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-
-  gpu_memory_stats_ = gpu_memory_stats;
-}
-
 // static
 void TaskManagerImpl::OnMultipleBytesReadUI(
     std::vector<BytesReadParam>* params) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   DCHECK(params);
 
   for (BytesReadParam& param : *params) {
     if (!GetInstance()->UpdateTasksWithBytesRead(param)) {
       // We can't match a task to the notification.  That might mean the
       // tab that started a download was closed, or the request may have had
       // no originating task associated with it in the first place.
       // We attribute orphaned/unaccounted activity to the Browser process.
       DCHECK(param.origin_pid || (param.child_id != -1));
 
       param.origin_pid = 0;
       param.child_id = param.route_id = -1;
 
       GetInstance()->UpdateTasksWithBytesRead(param);
     }
   }
 }
 
+void TaskManagerImpl::OnVideoMemoryUsageStatsUpdate(
+    const gpu::VideoMemoryUsageStats& gpu_memory_stats) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);

[jbauman, 2017/04/20 21:35:02]

Won't this be called on the IO thread if it's run directly from the mojo
callback?

[sadrul, 2017/04/21 03:41:01]

Very nice. Good catch! Yes, you are right. I missed the detail that
GpuDataManagerImplPrivate has a ObserverListThreadSafe instead of an
ObserverList. Thanks for catching this!

+
+  gpu_memory_stats_ = gpu_memory_stats;
+}
+
 void TaskManagerImpl::Refresh() {
   if (IsResourceRefreshEnabled(REFRESH_TYPE_GPU_MEMORY)) {
-    content::GpuDataManager::GetInstance()->
-        RequestVideoMemoryUsageStatsUpdate();
+    content::GpuDataManager::GetInstance()->RequestVideoMemoryUsageStatsUpdate(
+        base::Bind(&TaskManagerImpl::OnVideoMemoryUsageStatsUpdate,
+                   weak_ptr_factory_.GetWeakPtr()));
   }
 
   for (auto& groups_itr : task_groups_by_proc_id_) {
     groups_itr.second->Refresh(gpu_memory_stats_,
                                GetCurrentRefreshTime(),
                                enabled_resources_flags());
   }
 
   NotifyObserversOnRefresh(GetTaskIdsList());
 }
@@ skipping 70 matching lines @@
         groups_itr.second->AreBackgroundCalculationsDone();
   }
   if (are_all_processes_data_ready) {
     NotifyObserversOnRefreshWithBackgroundCalculations(GetTaskIdsList());
     for (const auto& groups_itr : task_groups_by_proc_id_)
       groups_itr.second->ClearCurrentBackgroundCalculationsFlags();
   }
 }
 
 }  // namespace task_manager