Migrate ProcessesEventRouter to the new task manager

chrome/browser/extensions/api/processes/processes_api.cc

Index: chrome/browser/extensions/api/processes/processes_api.cc
diff --git a/chrome/browser/extensions/api/processes/processes_api.cc b/chrome/browser/extensions/api/processes/processes_api.cc
index 4b6a14cd18ab34a3c245dfb4dc1cf003d8b1aa21..2f721b8c75f2c841afc52cf93e7801bbdfdd4507 100644
--- a/chrome/browser/extensions/api/processes/processes_api.cc
+++ b/chrome/browser/extensions/api/processes/processes_api.cc
@@ -4,475 +4,332 @@
 
 #include "chrome/browser/extensions/api/processes/processes_api.h"
 
-#include <stddef.h>
-#include <stdint.h>
-#include <utility>
-
-#include "base/callback.h"
-#include "base/json/json_writer.h"
 #include "base/lazy_instance.h"
-#include "base/location.h"
-#include "base/metrics/histogram.h"
-#include "base/single_thread_task_runner.h"
+#include "base/metrics/histogram_macros.h"
+#include "base/process/process.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
-#include "base/thread_task_runner_handle.h"
-#include "base/values.h"
-#include "chrome/browser/chrome_notification_types.h"
-#include "chrome/browser/extensions/api/processes/processes_api_constants.h"
 #include "chrome/browser/extensions/api/tabs/tabs_constants.h"
-#include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/profiles/profile.h"
-#include "chrome/browser/task_manager/resource_provider.h"
-#include "chrome/browser/task_manager/task_manager.h"
-#include "content/public/browser/browser_context.h"
-#include "content/public/browser/notification_details.h"
-#include "content/public/browser/notification_service.h"
-#include "content/public/browser/notification_source.h"
-#include "content/public/browser/notification_types.h"
+#include "chrome/browser/task_management/task_manager_interface.h"
+#include "chrome/common/extensions/api/processes.h"
+#include "content/public/browser/browser_child_process_host.h"
+#include "content/public/browser/child_process_data.h"
 #include "content/public/browser/render_process_host.h"
-#include "content/public/browser/render_view_host.h"
-#include "content/public/browser/render_widget_host.h"
-#include "content/public/browser/render_widget_host_iterator.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/result_codes.h"
-#include "extensions/browser/event_router.h"
-#include "extensions/browser/extension_function_registry.h"
-#include "extensions/browser/extension_function_util.h"
 #include "extensions/common/error_utils.h"
+#include "third_party/WebKit/public/web/WebCache.h"
 
 namespace extensions {
 
-namespace keys = processes_api_constants;
-namespace errors = processes_api_constants;
+namespace errors {
+const char kNotAllowedToTerminate[] = "Not allowed to terminate process: *.";
+const char kProcessNotFound[] = "Process not found: *.";
+}  // namespace errors
 
 namespace {
 
-#if defined(ENABLE_TASK_MANAGER)
+base::LazyInstance<BrowserContextKeyedAPIFactory<ProcessesAPI> >
+    g_processes_api_factory = LAZY_INSTANCE_INITIALIZER;
 
-base::DictionaryValue* CreateCacheData(
-    const blink::WebCache::ResourceTypeStat& stat) {
+api::processes::ProcessType GetProcessType(
+    task_management::Task::Type task_type) {
+  switch (task_type) {
+    case task_management::Task::BROWSER:
+      return api::processes::PROCESS_TYPE_BROWSER;
 
-  base::DictionaryValue* cache = new base::DictionaryValue();
-  cache->SetDouble(keys::kCacheSize, static_cast<double>(stat.size));
-  cache->SetDouble(keys::kCacheLiveSize, static_cast<double>(stat.liveSize));
-  return cache;
-}
+    case task_management::Task::RENDERER:
+      return api::processes::PROCESS_TYPE_RENDERER;
 
-void SetProcessType(base::DictionaryValue* result,
-                    TaskManagerModel* model,
-                    int index) {
-  // Determine process type.
-  std::string type = keys::kProcessTypeOther;
-  task_manager::Resource::Type resource_type = model->GetResourceType(index);
-  switch (resource_type) {
-    case task_manager::Resource::BROWSER:
-      type = keys::kProcessTypeBrowser;
-      break;
-    case task_manager::Resource::RENDERER:
-      type = keys::kProcessTypeRenderer;
-      break;
-    case task_manager::Resource::EXTENSION:
-      type = keys::kProcessTypeExtension;
-      break;
-    case task_manager::Resource::NOTIFICATION:
-      type = keys::kProcessTypeNotification;
-      break;
-    case task_manager::Resource::PLUGIN:
-      type = keys::kProcessTypePlugin;
-      break;
-    case task_manager::Resource::WORKER:
-      type = keys::kProcessTypeWorker;
-      break;
-    case task_manager::Resource::NACL:
-      type = keys::kProcessTypeNacl;
-      break;
-    case task_manager::Resource::UTILITY:
-      type = keys::kProcessTypeUtility;
-      break;
-    case task_manager::Resource::GPU:
-      type = keys::kProcessTypeGPU;
-      break;
-    case task_manager::Resource::ZYGOTE:
-    case task_manager::Resource::SANDBOX_HELPER:
-    case task_manager::Resource::UNKNOWN:
-      type = keys::kProcessTypeOther;
-      break;
-    default:
-      NOTREACHED() << "Unknown resource type.";
-  }
-  result->SetString(keys::kTypeKey, type);
-}
+    case task_management::Task::EXTENSION:
+    case task_management::Task::GUEST:
+      return api::processes::PROCESS_TYPE_EXTENSION;
 
-base::ListValue* GetTabsForProcess(int process_id) {
-  base::ListValue* tabs_list = new base::ListValue();
-
-  // The tabs list only makes sense for render processes, so if we don't find
-  // one, just return the empty list.
-  content::RenderProcessHost* rph =
-      content::RenderProcessHost::FromID(process_id);
-  if (rph == NULL)
-    return tabs_list;
-
-  int tab_id = -1;
-  // We need to loop through all the RVHs to ensure we collect the set of all
-  // tabs using this renderer process.
-  scoped_ptr<content::RenderWidgetHostIterator> widgets(
-      content::RenderWidgetHost::GetRenderWidgetHosts());
-  while (content::RenderWidgetHost* widget = widgets->GetNextHost()) {
-    if (widget->GetProcess()->GetID() != process_id)
-      continue;
+    case task_management::Task::PLUGIN:
+      return api::processes::PROCESS_TYPE_PLUGIN;
 
-    content::RenderViewHost* host = content::RenderViewHost::From(widget);
-    content::WebContents* contents =
-        content::WebContents::FromRenderViewHost(host);
-    if (contents) {
-      tab_id = ExtensionTabUtil::GetTabId(contents);
-      if (tab_id != -1)
-        tabs_list->Append(new base::FundamentalValue(tab_id));
-    }
+    case task_management::Task::WORKER:
+      return api::processes::PROCESS_TYPE_WORKER;
+
+    case task_management::Task::NACL:
+      return api::processes::PROCESS_TYPE_NACL;
+
+    case task_management::Task::UTILITY:
+      return api::processes::PROCESS_TYPE_UTILITY;
+
+    case task_management::Task::GPU:
+      return api::processes::PROCESS_TYPE_GPU;
+
+    case task_management::Task::UNKNOWN:
+    case task_management::Task::ARC:
+    case task_management::Task::SANDBOX_HELPER:
+    case task_management::Task::ZYGOTE:
+      return api::processes::PROCESS_TYPE_OTHER;
+
+    default:

[ncarter (slow), 2016/02/08 22:37:09]

If you omit the 'default' here and add a default-return after the switch, you
ought to be able to force a compile error if this enum is ever added to, which
seems desirable.

[afakhry, 2016/02/09 04:01:23]

Done.

+      NOTREACHED() << "Unknown task type.";
+      return api::processes::PROCESS_TYPE_OTHER;
   }
+}
 
-  return tabs_list;
+scoped_ptr<api::processes::Cache> CreateCacheData(
+    const blink::WebCache::ResourceTypeStat& stat) {
+  scoped_ptr<api::processes::Cache> cache(new api::processes::Cache);
+  cache->size = static_cast<double>(stat.size);
+  cache->live_size = static_cast<double>(stat.liveSize);
+  return cache;
 }
 
-// This function creates a Process object to be returned to the extensions
-// using these APIs. For memory details, which are not added by this function,
-// the callers need to use AddMemoryDetails.
-base::DictionaryValue* CreateProcessFromModel(int process_id,
-                                              TaskManagerModel* model,
-                                              int index,
-                                              bool include_optional) {
-  base::DictionaryValue* result = new base::DictionaryValue();
-  size_t mem;
-
-  result->SetInteger(keys::kIdKey, process_id);
-  result->SetInteger(keys::kOsProcessIdKey, model->GetProcessId(index));
-  SetProcessType(result, model, index);
-  result->SetString(keys::kTitleKey, model->GetResourceTitle(index));
-  result->SetString(keys::kProfileKey,
-      model->GetResourceProfileName(index));
-  result->SetInteger(keys::kNaClDebugPortKey,
-                     model->GetNaClDebugStubPort(index));
-
-  result->Set(keys::kTabsListKey, GetTabsForProcess(process_id));
+// Fills |out_process| with the data of the process in which the task with |id|
+// is running. If |include_optional| is true, this function will fill the
+// optional fields in |api::processes::Process| except for |private_memory|,
+// which should be filled later if needed.
+void FillProcessData(
+    api::processes::Process* out_process,

[ncarter (slow), 2016/02/08 22:37:09]

|out_process| ought to be the last parameter.--
https://google.github.io/styleguide/cppguide.html#Function_Parameter_Ordering

(or, can you change this function so that it returns a Process object?)

[afakhry, 2016/02/09 04:01:23]

Thanks for the pointer. Placed as the last parameter.

Process is non-copy-able. I could have returned scoped_ptr<Process>, but thought
it's too verbose.

+    task_management::TaskId id,
+    task_management::TaskManagerInterface* task_manager,
+    bool include_optional) {
+  out_process->id = task_manager->GetChildProcessUniqueId(id);
+  out_process->os_process_id = task_manager->GetProcessId(id);
+  out_process->type = GetProcessType(task_manager->GetType(id));
+  out_process->profile = base::UTF16ToUTF8(task_manager->GetProfileName(id));
+  out_process->nacl_debug_port = task_manager->GetNaClDebugStubPort(id);
+
+  // Collect the tab IDs of all the tasks sharing this renderer if any.
+  const task_management::TaskIdList tasks_on_process =
+      task_manager->GetIdsOfTasksSharingSameProcess(id);
+  for (const auto& task_id : tasks_on_process) {
+    linked_ptr<api::processes::TaskInfo> task_info(
+        new api::processes::TaskInfo);
+    task_info->title = base::UTF16ToUTF8(task_manager->GetTitle(task_id));
+    const int tab_id = task_manager->GetTabId(task_id);
+    if (tab_id != -1)
+      task_info->tab_id.reset(new int(tab_id));
+
+    out_process->tasks.push_back(task_info);
+  }
 
   // If we don't need to include the optional properties, just return now.
   if (!include_optional)
-    return result;
+    return;
 
-  result->SetDouble(keys::kCpuKey, model->GetCPUUsage(index));
+  out_process->cpu.reset(new double(task_manager->GetCpuUsage(id)));
 
-  if (model->GetV8Memory(index, &mem))
-    result->SetDouble(keys::kJsMemoryAllocatedKey,
-        static_cast<double>(mem));
+  out_process->network.reset(new double(static_cast<double>(
+      task_manager->GetProcessTotalNetworkUsage(id))));
 
-  if (model->GetV8MemoryUsed(index, &mem))
-    result->SetDouble(keys::kJsMemoryUsedKey,
-        static_cast<double>(mem));
+  int64_t v8_allocated;
+  int64_t v8_used;
+  if (task_manager->GetV8Memory(id, &v8_allocated, & v8_used)) {
+    out_process->js_memory_allocated.reset(new double(static_cast<double>(
+        v8_allocated)));
+    out_process->js_memory_used.reset(new double(static_cast<double>(v8_used)));
+  }
 
-  if (model->GetSqliteMemoryUsedBytes(index, &mem))
-    result->SetDouble(keys::kSqliteMemoryKey,
-        static_cast<double>(mem));
+  const int64_t sqlite_bytes = task_manager->GetSqliteMemoryUsed(id);
+  if (sqlite_bytes != -1) {
+    out_process->sqlite_memory.reset(new double(static_cast<double>(
+        sqlite_bytes)));
+  }
 
   blink::WebCache::ResourceTypeStats cache_stats;
-  if (model->GetWebCoreCacheStats(index, &cache_stats)) {
-    result->Set(keys::kImageCacheKey,
-                CreateCacheData(cache_stats.images));
-    result->Set(keys::kScriptCacheKey,
-                CreateCacheData(cache_stats.scripts));
-    result->Set(keys::kCssCacheKey,
-                CreateCacheData(cache_stats.cssStyleSheets));
+  if (task_manager->GetWebCacheStats(id, &cache_stats)) {
+    out_process->image_cache = CreateCacheData(cache_stats.images);
+    out_process->script_cache = CreateCacheData(cache_stats.scripts);
+    out_process->css_cache = CreateCacheData(cache_stats.cssStyleSheets);
   }
-
-  // Network is reported by the TaskManager per resource (tab), not per
-  // process, therefore we need to iterate through the group of resources
-  // and aggregate the data.
-  int64_t net = 0;
-  int length = model->GetGroupRangeForResource(index).second;
-  for (int i = 0; i < length; ++i)
-    net += model->GetNetworkUsage(index + i);
-  result->SetDouble(keys::kNetworkKey, static_cast<double>(net));
-
-  return result;
 }
 
-// Since memory details are expensive to gather, we don't do it by default.
-// This function is a helper to add memory details data to an existing
-// Process object representation.
-void AddMemoryDetails(base::DictionaryValue* result,
-                      TaskManagerModel* model,
-                      int index) {
-  size_t mem;
-  int64_t pr_mem =
-      model->GetPrivateMemory(index, &mem) ? static_cast<int64_t>(mem) : -1;
-  result->SetDouble(keys::kPrivateMemoryKey, static_cast<double>(pr_mem));
+int64_t GetRefreshTypesFlagOnlyEssentialData() {
+  // This is the only non-optional data in the Process as defined by the API in
+  // processes.idl.
+  return task_management::REFRESH_TYPE_NACL;
 }
 
-#endif  // defined(ENABLE_TASK_MANAGER)
+// This does not include memory. The memory refresh flag will only be added once
+// a listener to OnUpdatedWithMemory event is added.
+int64_t GetRefreshTypesFlagIncludeOptionalData() {
+  return GetRefreshTypesFlagOnlyEssentialData() |
+      task_management::REFRESH_TYPE_CPU |
+      task_management::REFRESH_TYPE_NETWORK_USAGE |
+      task_management::REFRESH_TYPE_SQLITE_MEMORY |
+      task_management::REFRESH_TYPE_V8_MEMORY |
+      task_management::REFRESH_TYPE_WEBCACHE_STATS;
+}
 
 }  // namespace
 
+////////////////////////////////////////////////////////////////////////////////
+// ProcessesEventRouter:
+////////////////////////////////////////////////////////////////////////////////
+
 ProcessesEventRouter::ProcessesEventRouter(content::BrowserContext* context)
-    : browser_context_(context), listeners_(0), task_manager_listening_(false) {
-#if defined(ENABLE_TASK_MANAGER)
-  model_ = TaskManager::GetInstance()->model();
-  model_->AddObserver(this);
-
-  registrar_.Add(this, content::NOTIFICATION_RENDER_WIDGET_HOST_HANG,
-      content::NotificationService::AllSources());
-  registrar_.Add(this, content::NOTIFICATION_RENDERER_PROCESS_CLOSED,
-      content::NotificationService::AllSources());
-#endif  // defined(ENABLE_TASK_MANAGER)
+    : task_management::TaskManagerObserver(
+          base::TimeDelta::FromSeconds(1),
+          GetRefreshTypesFlagIncludeOptionalData()),
+      browser_context_(context),
+      listeners_(0) {
 }
 
 ProcessesEventRouter::~ProcessesEventRouter() {
-#if defined(ENABLE_TASK_MANAGER)
-  registrar_.Remove(this, content::NOTIFICATION_RENDER_WIDGET_HOST_HANG,
-      content::NotificationService::AllSources());
-  registrar_.Remove(this, content::NOTIFICATION_RENDERER_PROCESS_CLOSED,
-      content::NotificationService::AllSources());
-
-  if (task_manager_listening_)
-    model_->StopListening();
-
-  model_->RemoveObserver(this);
-#endif  // defined(ENABLE_TASK_MANAGER)
+  if (observed_task_manager()) {
+    task_management::TaskManagerInterface::GetTaskManager()->RemoveObserver(
+        this);
+  }
 }
 
 void ProcessesEventRouter::ListenerAdded() {
-#if defined(ENABLE_TASK_MANAGER)
-  // The task manager has its own ref count to balance other callers of
-  // StartUpdating/StopUpdating.
-  model_->StartUpdating();
-#endif  // defined(ENABLE_TASK_MANAGER)
-  ++listeners_;
-}
-
-void ProcessesEventRouter::ListenerRemoved() {
-  DCHECK_GT(listeners_, 0);
-  --listeners_;
-#if defined(ENABLE_TASK_MANAGER)
-  // The task manager has its own ref count to balance other callers of
-  // StartUpdating/StopUpdating.
-  model_->StopUpdating();
-#endif  // defined(ENABLE_TASK_MANAGER)
-}
+  // Do we need to update memory usage?
+  if (HasEventListeners(api::processes::OnUpdatedWithMemory::kEventName))
+    AddRefreshType(task_management::REFRESH_TYPE_MEMORY);
 
-void ProcessesEventRouter::StartTaskManagerListening() {
-#if defined(ENABLE_TASK_MANAGER)
-  if (!task_manager_listening_) {
-    model_->StartListening();
-    task_manager_listening_ = true;
+  if (listeners_++ == 0) {
+   // The first listener to be added.
+   task_management::TaskManagerInterface::GetTaskManager()->AddObserver(this);
   }
-#endif  // defined(ENABLE_TASK_MANAGER)
 }
 
-void ProcessesEventRouter::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
-
-  switch (type) {
-    case content::NOTIFICATION_RENDER_WIDGET_HOST_HANG:
-      ProcessHangEvent(
-          content::Source<content::RenderWidgetHost>(source).ptr());
-      break;
-    case content::NOTIFICATION_RENDERER_PROCESS_CLOSED:
-      ProcessClosedEvent(
-          content::Source<content::RenderProcessHost>(source).ptr(),
-          content::Details<content::RenderProcessHost::RendererClosedDetails>(
-              details).ptr());
-      break;
-    default:
-      NOTREACHED() << "Unexpected observe of type " << type;
+void ProcessesEventRouter::ListenerRemoved() {
+  // No more listeners for memory usage?
+  if (!HasEventListeners(api::processes::OnUpdatedWithMemory::kEventName))
+    RemoveRefreshType(task_management::REFRESH_TYPE_MEMORY);
+
+  if (--listeners_ <= 0) {

[ncarter (slow), 2016/02/08 22:37:09]

Why not ==

[afakhry, 2016/02/09 04:01:23]

Done.

+    // Last listener to be removed.
+    task_management::TaskManagerInterface::GetTaskManager()->RemoveObserver(
+        this);
   }
-  return;
 }
 
-void ProcessesEventRouter::OnItemsAdded(int start, int length) {
-#if defined(ENABLE_TASK_MANAGER)
-  DCHECK_EQ(length, 1);
-  int index = start;
-
-  std::string event(keys::kOnCreated);
-  if (!HasEventListeners(event))
+void ProcessesEventRouter::OnTaskAdded(task_management::TaskId id) {
+  if (!HasEventListeners(api::processes::OnCreated::kEventName))
     return;
 
-  // If the item being added is not the first one in the group, find the base
-  // index and use it for retrieving the process data.
-  if (!model_->IsResourceFirstInGroup(start)) {
-    index = model_->GetGroupIndexForResource(start);
-  }
-
-  scoped_ptr<base::ListValue> args(new base::ListValue());
-  base::DictionaryValue* process = CreateProcessFromModel(
-      model_->GetUniqueChildProcessId(index), model_, index, false);
-  DCHECK(process != NULL);
-
-  if (process == NULL)
+  // Is this the first task to be created on the process and hence its creation
+  // corresponds to the creation of the process?
+  if (observed_task_manager()->GetNumberOfTasksOnSameProcess(id) != 1)
     return;
 
-  args->Append(process);
+  // Ignore tasks that don't have a child host ID that is greater than 0 (i.e.
+  // browser process task, ARC tasks).
+  if (observed_task_manager()->GetChildProcessUniqueId(id) <= 0)
+    return;
 
-  DispatchEvent(events::PROCESSES_ON_CREATED, keys::kOnCreated,
-                std::move(args));
-#endif  // defined(ENABLE_TASK_MANAGER)
+  api::processes::Process process;
+  FillProcessData(&process, id, observed_task_manager(), false);
+  DispatchEvent(events::PROCESSES_ON_CREATED,
+                api::processes::OnCreated::kEventName,
+                api::processes::OnCreated::Create(process));
 }
 
-void ProcessesEventRouter::OnItemsChanged(int start, int length) {
-#if defined(ENABLE_TASK_MANAGER)
-  // If we don't have any listeners, return immediately.
-  if (listeners_ == 0)
+void ProcessesEventRouter::OnTaskToBeRemoved(task_management::TaskId id) {
+  if (!HasEventListeners(api::processes::OnExited::kEventName))
     return;
 
-  if (!model_)
+  // Is this the last task to be removed from the process, and hence its removal
+  // corresponds to the termination of the process?
+  if (observed_task_manager()->GetNumberOfTasksOnSameProcess(id) != 1)
     return;
 
-  // We need to know which type of onUpdated events to fire and whether to
-  // collect memory or not.
-  std::string updated_event(keys::kOnUpdated);
-  std::string updated_event_memory(keys::kOnUpdatedWithMemory);
-  bool updated = HasEventListeners(updated_event);
-  bool updated_memory = HasEventListeners(updated_event_memory);
-
-  DCHECK(updated || updated_memory);
-
-  IDMap<base::DictionaryValue> processes_map;
-  for (int i = start; i < start + length; i++) {
-    if (model_->IsResourceFirstInGroup(i)) {
-      int id = model_->GetUniqueChildProcessId(i);
-      base::DictionaryValue* process = CreateProcessFromModel(id, model_, i,
-                                                              true);
-      processes_map.AddWithID(process, i);
-    }
-  }
-
-  int id;
-  std::string idkey(keys::kIdKey);
-  base::DictionaryValue* processes = new base::DictionaryValue();
-
-  if (updated) {
-    IDMap<base::DictionaryValue>::iterator it(&processes_map);
-    for (; !it.IsAtEnd(); it.Advance()) {
-      if (!it.GetCurrentValue()->GetInteger(idkey, &id))
-        continue;
-
-      // Store each process indexed by the string version of its id.
-      processes->Set(base::IntToString(id), it.GetCurrentValue());
-    }
-
-    scoped_ptr<base::ListValue> args(new base::ListValue());
-    args->Append(processes);
-    DispatchEvent(events::PROCESSES_ON_UPDATED, keys::kOnUpdated,
-                  std::move(args));
-  }
-
-  if (updated_memory) {
-    IDMap<base::DictionaryValue>::iterator it(&processes_map);
-    for (; !it.IsAtEnd(); it.Advance()) {
-      if (!it.GetCurrentValue()->GetInteger(idkey, &id))
-        continue;
-
-      AddMemoryDetails(it.GetCurrentValue(), model_, it.GetCurrentKey());
-
-      // Store each process indexed by the string version of its id if we didn't
-      // already insert it as part of the onUpdated processing above.
-      if (!updated)
-        processes->Set(base::IntToString(id), it.GetCurrentValue());
-    }
-
-    scoped_ptr<base::ListValue> args(new base::ListValue());
-    args->Append(processes);
-    DispatchEvent(events::PROCESSES_ON_UPDATED_WITH_MEMORY,
-                  keys::kOnUpdatedWithMemory, std::move(args));
-  }
-#endif  // defined(ENABLE_TASK_MANAGER)
-}
-
-void ProcessesEventRouter::OnItemsToBeRemoved(int start, int length) {
-#if defined(ENABLE_TASK_MANAGER)
-  DCHECK_EQ(length, 1);
-
-  // Process exit for renderer processes has the data about exit code and
-  // termination status, therefore we will rely on notifications and not on
-  // the Task Manager data. We do use the rest of this method for non-renderer
-  // processes.
-  if (model_->GetResourceType(start) == task_manager::Resource::RENDERER)
+  // Ignore tasks that don't have a child host ID that is greater than 0 (i.e.
+  // browser process task, ARC tasks).
+  if (observed_task_manager()->GetChildProcessUniqueId(id) <= 0)
     return;
 
-  // The callback function parameters.
-  scoped_ptr<base::ListValue> args(new base::ListValue());
-
-  // First arg: The id of the process that was closed.
-  args->Append(new base::FundamentalValue(
-      model_->GetUniqueChildProcessId(start)));
-
-  // Second arg: The exit type for the process.
-  args->Append(new base::FundamentalValue(0));
+  int exit_code = 0;
+  base::TerminationStatus status = base::TERMINATION_STATUS_STILL_RUNNING;
+  observed_task_manager()->GetTerminationStatus(id, &status, &exit_code);
 
-  // Third arg: The exit code for the process.
-  args->Append(new base::FundamentalValue(0));
+  DispatchEvent(events::PROCESSES_ON_EXITED,
+                api::processes::OnExited::kEventName,
+                api::processes::OnExited::Create(
+                    observed_task_manager()->GetChildProcessUniqueId(id),
+                    status,
+                    exit_code));
 
-  DispatchEvent(events::PROCESSES_ON_EXITED, keys::kOnExited, std::move(args));
-#endif  // defined(ENABLE_TASK_MANAGER)
 }
 
-void ProcessesEventRouter::ProcessHangEvent(content::RenderWidgetHost* widget) {
-#if defined(ENABLE_TASK_MANAGER)
-  std::string event(keys::kOnUnresponsive);
-  if (!HasEventListeners(event))
+void ProcessesEventRouter::OnTasksRefreshed(
+    const task_management::TaskIdList& task_ids) {
+  const bool has_on_updated_listeners =
+      HasEventListeners(api::processes::OnUpdated::kEventName);
+  const bool has_on_updated_with_memory_listeners =
+      HasEventListeners(api::processes::OnUpdatedWithMemory::kEventName);
+
+  if (!has_on_updated_listeners && !has_on_updated_with_memory_listeners)
     return;
 
-  base::DictionaryValue* process = NULL;
-  int count = model_->ResourceCount();
-  int id = widget->GetProcess()->GetID();
+  // Get the data of tasks sharing the same process only once.
+  std::set<base::ProcessId> seen_processes;
+  base::DictionaryValue processes_dictionary;
+  for (const auto& task_id : task_ids) {
+    // We are not interested in tasks, but rather the processes on which they
+    // run.
+    const base::ProcessId proc_id =
+        observed_task_manager()->GetProcessId(task_id);
+    if (seen_processes.count(proc_id))
+      continue;
 
-  for (int i = 0; i < count; ++i) {
-    if (model_->IsResourceFirstInGroup(i)) {
-      if (id == model_->GetUniqueChildProcessId(i)) {
-        process = CreateProcessFromModel(id, model_, i, false);
-        break;
-      }
+    seen_processes.insert(proc_id);
+    const int child_process_host_id =
+        observed_task_manager()->GetChildProcessUniqueId(task_id);
+    api::processes::Process process;
+    FillProcessData(&process, task_id, observed_task_manager(), true);
+
+    if (has_on_updated_with_memory_listeners) {
+      // Append the private memory usage to the process data.
+      const int64_t private_memory =
+          observed_task_manager()->GetPrivateMemoryUsage(task_id);
+      process.private_memory.reset(new double(static_cast<double>(
+          private_memory)));
     }
-  }
 
-  if (process == NULL)
-    return;
+    // Store each process indexed by the string version of its ChildProcessHost
+    // ID.
+    processes_dictionary.Set(base::IntToString(child_process_host_id),
+                             process.ToValue());
+  }
 
-  scoped_ptr<base::ListValue> args(new base::ListValue());
-  args->Append(process);
+  // Done with data collection. Now dispatch the appropriate events according to
+  // the present listeners.
+  DCHECK(has_on_updated_listeners || has_on_updated_with_memory_listeners);
+  if (has_on_updated_listeners) {
+    api::processes::OnUpdated::Processes processes;
+    processes.additional_properties.MergeDictionary(&processes_dictionary);
+    // NOTE: If there are listeners to the updates with memory as well,
+    // listeners to onUpdated (without memory) will also get the memory info
+    // of processes as an added bonus.
+    DispatchEvent(events::PROCESSES_ON_UPDATED,
+                  api::processes::OnUpdated::kEventName,
+                  api::processes::OnUpdated::Create(processes));
+  }
 
-  DispatchEvent(events::PROCESSES_ON_UNRESPONSIVE, keys::kOnUnresponsive,
-                std::move(args));
-#endif  // defined(ENABLE_TASK_MANAGER)
+  if (has_on_updated_with_memory_listeners) {
+    api::processes::OnUpdatedWithMemory::Processes processes;
+    processes.additional_properties.MergeDictionary(&processes_dictionary);
+    DispatchEvent(events::PROCESSES_ON_UPDATED_WITH_MEMORY,
+                  api::processes::OnUpdatedWithMemory::kEventName,
+                  api::processes::OnUpdatedWithMemory::Create(processes));
+  }
 }
 
-void ProcessesEventRouter::ProcessClosedEvent(
-    content::RenderProcessHost* rph,
-    content::RenderProcessHost::RendererClosedDetails* details) {
-#if defined(ENABLE_TASK_MANAGER)
-  // The callback function parameters.
-  scoped_ptr<base::ListValue> args(new base::ListValue());
-
-  // First arg: The id of the process that was closed.
-  args->Append(new base::FundamentalValue(rph->GetID()));
-
-  // Second arg: The exit type for the process.
-  args->Append(new base::FundamentalValue(details->status));
-
-  // Third arg: The exit code for the process.
-  args->Append(new base::FundamentalValue(details->exit_code));
+void ProcessesEventRouter::OnTaskUnresponsive(task_management::TaskId id) {
+  if (!HasEventListeners(api::processes::OnUnresponsive::kEventName))
+    return;
 
-  DispatchEvent(events::PROCESSES_ON_EXITED, keys::kOnExited, std::move(args));
-#endif  // defined(ENABLE_TASK_MANAGER)
+  api::processes::Process process;
+  FillProcessData(&process, id, observed_task_manager(), false);
+  DispatchEvent(events::PROCESSES_ON_UNRESPONSIVE,
+                api::processes::OnUnresponsive::kEventName,
+                api::processes::OnUnresponsive::Create(process));
 }
 
 void ProcessesEventRouter::DispatchEvent(
     events::HistogramValue histogram_value,
     const std::string& event_name,
-    scoped_ptr<base::ListValue> event_args) {
+    scoped_ptr<base::ListValue> event_args) const {
   EventRouter* event_router = EventRouter::Get(browser_context_);
   if (event_router) {
     scoped_ptr<Event> event(
@@ -481,54 +338,53 @@ void ProcessesEventRouter::DispatchEvent(
   }
 }
 
-bool ProcessesEventRouter::HasEventListeners(const std::string& event_name) {
+bool ProcessesEventRouter::HasEventListeners(
+    const std::string& event_name) const {
   EventRouter* event_router = EventRouter::Get(browser_context_);
   return event_router && event_router->HasEventListener(event_name);
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// ProcessesAPI:
+////////////////////////////////////////////////////////////////////////////////
+
 ProcessesAPI::ProcessesAPI(content::BrowserContext* context)
     : browser_context_(context) {
   EventRouter* event_router = EventRouter::Get(browser_context_);
-  event_router->RegisterObserver(this, processes_api_constants::kOnUpdated);
+  // Monitor when the following events are being listened to in order to know
+  // when to start the task manager.
+  event_router->RegisterObserver(this, api::processes::OnUpdated::kEventName);
+  event_router->RegisterObserver(
+      this, api::processes::OnUpdatedWithMemory::kEventName);
+  event_router->RegisterObserver(this, api::processes::OnCreated::kEventName);
   event_router->RegisterObserver(this,
-                                 processes_api_constants::kOnUpdatedWithMemory);
-  ExtensionFunctionRegistry* registry =
-      ExtensionFunctionRegistry::GetInstance();
-  registry->RegisterFunction<GetProcessIdForTabFunction>();
-  registry->RegisterFunction<TerminateFunction>();
-  registry->RegisterFunction<GetProcessInfoFunction>();
+                                 api::processes::OnUnresponsive::kEventName);
+  event_router->RegisterObserver(this, api::processes::OnExited::kEventName);
 }
 
 ProcessesAPI::~ProcessesAPI() {
+  // This object has already been unregistered as an observer in Shutdown().
 }
 
-void ProcessesAPI::Shutdown() {
-  EventRouter::Get(browser_context_)->UnregisterObserver(this);
+// static
+ProcessesAPI* ProcessesAPI::Get(content::BrowserContext* context) {
+  return BrowserContextKeyedAPIFactory<ProcessesAPI>::Get(context);
 }
 
-static base::LazyInstance<BrowserContextKeyedAPIFactory<ProcessesAPI> >
-    g_factory = LAZY_INSTANCE_INITIALIZER;
-
 // static
 BrowserContextKeyedAPIFactory<ProcessesAPI>*
 ProcessesAPI::GetFactoryInstance() {
-  return g_factory.Pointer();
+  return g_processes_api_factory.Pointer();
 }
 
-// static
-ProcessesAPI* ProcessesAPI::Get(content::BrowserContext* context) {
-  return BrowserContextKeyedAPIFactory<ProcessesAPI>::Get(context);
-}
-
-ProcessesEventRouter* ProcessesAPI::processes_event_router() {
-  if (!processes_event_router_)
-    processes_event_router_.reset(new ProcessesEventRouter(browser_context_));
-  return processes_event_router_.get();
+void ProcessesAPI::Shutdown() {
+  EventRouter::Get(browser_context_)->UnregisterObserver(this);
 }
 
 void ProcessesAPI::OnListenerAdded(const EventListenerInfo& details) {
-  // We lazily tell the TaskManager to start updating when listeners to the
-  // processes.onUpdated or processes.onUpdatedWithMemory events arrive.
+  // The ProcessesEventRouter will observe the TaskManager as long as there are
+  // listeners for the processes.onUpdated or processes.onUpdatedWithMemory
+  // events.
   processes_event_router()->ListenerAdded();
 }
 
@@ -539,247 +395,219 @@ void ProcessesAPI::OnListenerRemoved(const EventListenerInfo& details) {
   processes_event_router()->ListenerRemoved();
 }
 
-GetProcessIdForTabFunction::GetProcessIdForTabFunction() : tab_id_(-1) {
+ProcessesEventRouter* ProcessesAPI::processes_event_router() {
+  if (!processes_event_router_.get())
+    processes_event_router_.reset(new ProcessesEventRouter(browser_context_));
+  return processes_event_router_.get();
 }
 
-bool GetProcessIdForTabFunction::RunAsync() {
-#if defined(ENABLE_TASK_MANAGER)
-  EXTENSION_FUNCTION_VALIDATE(args_->GetInteger(0, &tab_id_));
+////////////////////////////////////////////////////////////////////////////////
+// ProcessesTerminateFunction:
+////////////////////////////////////////////////////////////////////////////////
 
-  // Add a reference, which is balanced in GetProcessIdForTab to keep the object
-  // around and allow for the callback to be invoked.
-  AddRef();
+ExtensionFunction::ResponseAction ProcessesTerminateFunction::Run() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
-  // If the task manager is already listening, just post a task to execute
-  // which will invoke the callback once we have returned from this function.
-  // Otherwise, wait for the notification that the task manager is done with
-  // the data gathering.
-  if (ProcessesAPI::Get(GetProfile())
-          ->processes_event_router()
-          ->is_task_manager_listening()) {
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE,
-        base::Bind(&GetProcessIdForTabFunction::GetProcessIdForTab, this));
-  } else {
-    TaskManager::GetInstance()->model()->RegisterOnDataReadyCallback(
-        base::Bind(&GetProcessIdForTabFunction::GetProcessIdForTab, this));
-
-    ProcessesAPI::Get(GetProfile())
-        ->processes_event_router()
-        ->StartTaskManagerListening();
+  // For this function, the task manager doesn't even need to be running.
+  scoped_ptr<api::processes::Terminate::Params> params(
+      api::processes::Terminate::Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params.get());
+
+  child_process_host_id_ = params->process_id;
+  if (child_process_host_id_ == 0) {
+    // Cannot kill the browser process.
+    return RespondNow(Error(errors::kNotAllowedToTerminate,
+                            base::IntToString(child_process_host_id_)));
   }
 
-  return true;
-#else
-  error_ = errors::kExtensionNotSupported;
-  return false;
-#endif  // defined(ENABLE_TASK_MANAGER)
+  content::BrowserThread::PostTaskAndReplyWithResult(
+      content::BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&ProcessesTerminateFunction::GetProcessHandleIO,
+                 this,
+                 child_process_host_id_),
+      base::Bind(&ProcessesTerminateFunction::OnProcessHandleUI, this));
+
+  // Promise to respond later.
+  return RespondLater();
 }
 
-void GetProcessIdForTabFunction::GetProcessIdForTab() {
-  content::WebContents* contents = NULL;
-  int tab_index = -1;
-  if (!ExtensionTabUtil::GetTabById(tab_id_,
-                                    GetProfile(),
-                                    include_incognito(),
-                                    NULL,
-                                    NULL,
-                                    &contents,
-                                    &tab_index)) {
-    error_ = ErrorUtils::FormatErrorMessage(tabs_constants::kTabNotFoundError,
-                                            base::IntToString(tab_id_));
-    SetResult(new base::FundamentalValue(-1));
-    SendResponse(false);
-  } else {
-    int process_id = contents->GetRenderProcessHost()->GetID();
-    SetResult(new base::FundamentalValue(process_id));
-    SendResponse(true);
-  }
+base::ProcessHandle ProcessesTerminateFunction::GetProcessHandleIO(
+    int child_process_host_id) const {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
 
-  // Balance the AddRef in the RunAsync.
-  Release();
-}
+  auto* host = content::BrowserChildProcessHost::FromID(child_process_host_id);
+  if (host)
+    return host->GetData().handle;
 
-TerminateFunction::TerminateFunction() : process_id_(-1) {
+  return base::kNullProcessHandle;
 }
 
-bool TerminateFunction::RunAsync() {
-#if defined(ENABLE_TASK_MANAGER)
-  EXTENSION_FUNCTION_VALIDATE(args_->GetInteger(0, &process_id_));
+void ProcessesTerminateFunction::OnProcessHandleUI(base::ProcessHandle handle) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
-  // Add a reference, which is balanced in TerminateProcess to keep the object
-  // around and allow for the callback to be invoked.
-  AddRef();
+  if (handle == base::kNullProcessHandle) {
+    // If we didn't get anything from BrowserChildProcessHost, then it could be
+    // a renderer.
+    auto* render_host =
+        content::RenderProcessHost::FromID(child_process_host_id_);
+    if (render_host)
+      handle = render_host->GetHandle();
+  }
 
-  // If the task manager is already listening, just post a task to execute
-  // which will invoke the callback once we have returned from this function.
-  // Otherwise, wait for the notification that the task manager is done with
-  // the data gathering.
-  if (ProcessesAPI::Get(GetProfile())
-          ->processes_event_router()
-          ->is_task_manager_listening()) {
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(&TerminateFunction::TerminateProcess, this));
-  } else {
-    TaskManager::GetInstance()->model()->RegisterOnDataReadyCallback(
-        base::Bind(&TerminateFunction::TerminateProcess, this));
-
-    ProcessesAPI::Get(GetProfile())
-        ->processes_event_router()
-        ->StartTaskManagerListening();
+  if (handle == base::kNullProcessHandle) {
+    Respond(Error(errors::kProcessNotFound,
+                  base::IntToString(child_process_host_id_)));
+    return;
   }
 
-  return true;
-#else
-  error_ = errors::kExtensionNotSupported;
-  return false;
-#endif  // defined(ENABLE_TASK_MANAGER)
+  if (handle == base::GetCurrentProcessHandle()) {
+    // Cannot kill the browser process.
+    Respond(Error(errors::kNotAllowedToTerminate,
+                  base::IntToString(child_process_host_id_)));
+    return;
+  }
+
+  base::Process process = base::Process::Open(base::GetProcId(handle));
+  const bool did_terminate =
+      process.Terminate(content::RESULT_CODE_KILLED, true);
+  if (did_terminate)
+    UMA_HISTOGRAM_COUNTS("ChildProcess.KilledByExtensionAPI", 1);
+
+  Respond(ArgumentList(
+      api::processes::Terminate::Results::Create(did_terminate)));
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// ProcessesGetProcessIdForTabFunction:
+////////////////////////////////////////////////////////////////////////////////
 
-void TerminateFunction::TerminateProcess() {
-#if defined(ENABLE_TASK_MANAGER)
-  TaskManagerModel* model = TaskManager::GetInstance()->model();
+ExtensionFunction::ResponseAction ProcessesGetProcessIdForTabFunction::Run() {
+  // For this function, the task manager doesn't even need to be running.
+  scoped_ptr<api::processes::GetProcessIdForTab::Params> params(
+      api::processes::GetProcessIdForTab::Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params.get());
 
-  bool found = false;
-  for (int i = 0, count = model->ResourceCount(); i < count; ++i) {
-    if (!model->IsResourceFirstInGroup(i) ||
-        process_id_ != model->GetUniqueChildProcessId(i)) {
-      continue;
-    }
-    base::ProcessHandle process_handle = model->GetProcess(i);
-    if (process_handle == base::GetCurrentProcessHandle()) {
-      // Cannot kill the browser process.
-      // TODO(kalman): Are there other sensitive processes?
-      error_ = ErrorUtils::FormatErrorMessage(errors::kNotAllowedToTerminate,
-                                              base::IntToString(process_id_));
-    } else {
-      base::Process process =
-          base::Process::DeprecatedGetProcessFromHandle(process_handle);
-      bool did_terminate = process.Terminate(content::RESULT_CODE_KILLED, true);
-      if (did_terminate)
-        UMA_HISTOGRAM_COUNTS("ChildProcess.KilledByExtensionAPI", 1);
-      SetResult(new base::FundamentalValue(did_terminate));
-    }
-    found = true;
-    break;
-  }
-  if (!found) {
-    error_ = ErrorUtils::FormatErrorMessage(errors::kProcessNotFound,
-                                            base::IntToString(process_id_));
+  const int tab_id = params->tab_id;
+  content::WebContents* contents = nullptr;
+  int tab_index = -1;
+  if (!ExtensionTabUtil::GetTabById(
+          tab_id,
+          Profile::FromBrowserContext(browser_context()),
+          include_incognito(),
+          nullptr,
+          nullptr,
+          &contents,
+          &tab_index)) {
+    return RespondNow(Error(tabs_constants::kTabNotFoundError,
+                            base::IntToString(tab_id)));
   }
 
-  SendResponse(error_.empty());
-
-  // Balance the AddRef in the RunAsync.
-  Release();
-#else
-  error_ = errors::kExtensionNotSupported;
-  SendResponse(false);
-#endif  // defined(ENABLE_TASK_MANAGER)
+  const int process_id = contents->GetRenderProcessHost()->GetID();
+  return RespondNow(ArgumentList(
+      api::processes::GetProcessIdForTab::Results::Create(process_id)));
 }
 
-GetProcessInfoFunction::GetProcessInfoFunction()
-#if defined(ENABLE_TASK_MANAGER)
-  : memory_(false)
-#endif
-    {
-}
+////////////////////////////////////////////////////////////////////////////////
+// ProcessesGetProcessInfoFunction:
+////////////////////////////////////////////////////////////////////////////////
 
-GetProcessInfoFunction::~GetProcessInfoFunction() {
+ProcessesGetProcessInfoFunction::ProcessesGetProcessInfoFunction()
+    : task_management::TaskManagerObserver(
+          base::TimeDelta::FromSeconds(1),
+          GetRefreshTypesFlagOnlyEssentialData()) {
 }
 
-bool GetProcessInfoFunction::RunAsync() {
-#if defined(ENABLE_TASK_MANAGER)
-  base::Value* processes = NULL;
+ExtensionFunction::ResponseAction ProcessesGetProcessInfoFunction::Run() {
+  scoped_ptr<api::processes::GetProcessInfo::Params> params(
+      api::processes::GetProcessInfo::Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params.get());
+  if (params->process_ids.as_integer)
+    process_host_ids_.push_back(*params->process_ids.as_integer);
+  else
+    process_host_ids_.swap(*params->process_ids.as_integers);
+  include_memory_ = params->include_memory;
 
-  EXTENSION_FUNCTION_VALIDATE(args_->Get(0, &processes));
-  EXTENSION_FUNCTION_VALIDATE(args_->GetBoolean(1, &memory_));
-  EXTENSION_FUNCTION_VALIDATE(ReadOneOrMoreIntegers(processes, &process_ids_));
-
-  // Add a reference, which is balanced in GatherProcessInfo to keep the object
-  // around and allow for the callback to be invoked.
+  // Keep this object alive until the OnTasksRefreshed() is received.
   AddRef();
 
-  // If the task manager is already listening, just post a task to execute
-  // which will invoke the callback once we have returned from this function.
-  // Otherwise, wait for the notification that the task manager is done with
-  // the data gathering.
-  if (ProcessesAPI::Get(GetProfile())
-          ->processes_event_router()
-          ->is_task_manager_listening()) {
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE,
-        base::Bind(&GetProcessInfoFunction::GatherProcessInfo, this));
-  } else {
-    TaskManager::GetInstance()->model()->RegisterOnDataReadyCallback(
-        base::Bind(&GetProcessInfoFunction::GatherProcessInfo, this));
-
-    ProcessesAPI::Get(GetProfile())
-        ->processes_event_router()
-        ->StartTaskManagerListening();
-  }
-  return true;
+  // The task manager needs to be enabled for this function.
+  // Start observing the task manager and wait for the next refresh event.
+  task_management::TaskManagerInterface::GetTaskManager()->AddObserver(this);
 
-#else
-  error_ = errors::kExtensionNotSupported;
-  return false;
-#endif  // defined(ENABLE_TASK_MANAGER)
+  return RespondLater();
 }
 
-void GetProcessInfoFunction::GatherProcessInfo() {
-#if defined(ENABLE_TASK_MANAGER)
-  TaskManagerModel* model = TaskManager::GetInstance()->model();
-  base::DictionaryValue* processes = new base::DictionaryValue();
-
+void ProcessesGetProcessInfoFunction::OnTasksRefreshed(
+    const task_management::TaskIdList& task_ids) {
   // If there are no process IDs specified, it means we need to return all of
   // the ones we know of.
-  if (process_ids_.size() == 0) {
-    int resources = model->ResourceCount();
-    for (int i = 0; i < resources; ++i) {
-      if (model->IsResourceFirstInGroup(i)) {
-        int id = model->GetUniqueChildProcessId(i);
-        base::DictionaryValue* d = CreateProcessFromModel(id, model, i, false);
-        if (memory_)
-          AddMemoryDetails(d, model, i);
-        processes->Set(base::IntToString(id), d);
-      }
-    }
-  } else {
-    int resources = model->ResourceCount();
-    for (int i = 0; i < resources; ++i) {
-      if (model->IsResourceFirstInGroup(i)) {
-        int id = model->GetUniqueChildProcessId(i);
-        std::vector<int>::iterator proc_id = std::find(process_ids_.begin(),
-                                                       process_ids_.end(), id);
-        if (proc_id != process_ids_.end()) {
-          base::DictionaryValue* d =
-              CreateProcessFromModel(id, model, i, false);
-          if (memory_)
-            AddMemoryDetails(d, model, i);
-          processes->Set(base::IntToString(id), d);
-
-          process_ids_.erase(proc_id);
-          if (process_ids_.size() == 0)
-            break;
-        }
-      }
+  const bool specific_processes_requested = !process_host_ids_.empty();
+  std::set<base::ProcessId> seen_processes;
+  // Create the results object as defined in the generated API from process.idl
+  // and fill it with the processes info.
+  api::processes::GetProcessInfo::Results::Processes processes;
+  for (const auto& task_id : task_ids) {
+    const base::ProcessId proc_id =
+        observed_task_manager()->GetProcessId(task_id);
+    if (seen_processes.count(proc_id))
+      continue;
+
+    const int child_process_host_id =
+        observed_task_manager()->GetChildProcessUniqueId(task_id);
+
+    if (specific_processes_requested) {
+      // Note: we can't use |!process_host_ids_.empty()| directly in the above
+      // condition as we will erase from |process_host_ids_| below.
+      auto itr = std::find(process_host_ids_.begin(),
+                           process_host_ids_.end(),
+                           child_process_host_id);
+      if (itr == process_host_ids_.end())
+        continue;
+
+      // If found, we remove it from |process_host_ids|, so that at the end if
+      // anything remains in |process_host_ids|, those were invalid arguments
+      // that will be reported on the console.
+      process_host_ids_.erase(itr);
     }
-    // If not all processes were found, log them to the extension's console to
-    // help the developer, but don't fail the API call.
-    for (int pid : process_ids_) {
-      WriteToConsole(content::CONSOLE_MESSAGE_LEVEL_ERROR,
-                     ErrorUtils::FormatErrorMessage(errors::kProcessNotFound,
-                                                    base::IntToString(pid)));
+
+    seen_processes.insert(proc_id);
+
+    // We do not include the optional data in this function results.
+    api::processes::Process process;
+    FillProcessData(&process, task_id, observed_task_manager(), false);
+
+    if (include_memory_) {
+      // Append the private memory usage to the process data.
+      const int64_t private_memory =
+          observed_task_manager()->GetPrivateMemoryUsage(task_id);
+      process.private_memory.reset(new double(static_cast<double>(
+          private_memory)));
     }
+
+    // Store each process indexed by the string version of its
+    // ChildProcessHost ID.
+    processes.additional_properties.Set(
+        base::IntToString(child_process_host_id),
+        process.ToValue());
+  }
+
+  // Report the invalid host ids sent in the arguments.
+  for (const auto& host_id : process_host_ids_) {
+    WriteToConsole(content::CONSOLE_MESSAGE_LEVEL_ERROR,
+                   ErrorUtils::FormatErrorMessage(errors::kProcessNotFound,
+                                                  base::IntToString(host_id)));
   }
 
-  SetResult(processes);
-  SendResponse(true);
+  // Send the response.
+  Respond(ArgumentList(
+      api::processes::GetProcessInfo::Results::Create(processes)));
 
-  // Balance the AddRef in the RunAsync.
+  // Stop observing the task manager, and balance the AddRef() in Run().
+  task_management::TaskManagerInterface::GetTaskManager()->RemoveObserver(this);
   Release();
-#endif  // defined(ENABLE_TASK_MANAGER)
 }
 
+ProcessesGetProcessInfoFunction::~ProcessesGetProcessInfoFunction() {}
+
 }  // namespace extensions