Refactor CrashDump*Manager to use a shared CrashDumpObserver singleton.

components/crash/content/browser/crash_dump_observer_android.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 "components/crash/content/browser/crash_dump_observer_android.h"
+
+#include <unistd.h>
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "base/stl_util.h"
+#include "base/threading/sequenced_worker_pool.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/child_process_data.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/browser/notification_types.h"
+#include "content/public/browser/render_process_host.h"
+
+using content::BrowserThread;
+
+namespace breakpad {
+
+namespace {
+base::LazyInstance<CrashDumpObserver> g_instance = LAZY_INSTANCE_INITIALIZER;
+}
+
+// static
+void CrashDumpObserver::Create() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(g_instance == nullptr);

[Bernhard Bauer, 2016/12/08 17:41:25]

Maybe add a comment that if this check fails in a unit test, someone who was
previously creating the object forgot to use ShadowingAtExitManager? That might
not be totally obvious.

[Tobias Sargeant, 2016/12/12 11:49:51]

Done.

+  g_instance.Get();
+}
+
+// static
+CrashDumpObserver* CrashDumpObserver::GetInstance() {
+  DCHECK(!(g_instance == nullptr));
+  return g_instance.Pointer();
+}
+
+CrashDumpObserver::CrashDumpObserver() {
+  notification_registrar_.Add(this,
+                              content::NOTIFICATION_RENDERER_PROCESS_TERMINATED,
+                              content::NotificationService::AllSources());
+  notification_registrar_.Add(this,
+                              content::NOTIFICATION_RENDERER_PROCESS_CLOSED,
+                              content::NotificationService::AllSources());
+  BrowserChildProcessObserver::Add(this);
+}
+
+CrashDumpObserver::~CrashDumpObserver() {
+  BrowserChildProcessObserver::Remove(this);
+  base::AutoLock auto_lock(registered_clients_lock_);

[Bernhard Bauer, 2016/12/08 17:41:25]

I'm not sure you really need the lock here -- if the object is being destroyed,
no one should be using it anymore anyway.

[Tobias Sargeant, 2016/12/12 11:49:51]

Removed it (and the explicit clear of registered_clients_). I guess with or
without this there's an implicit requirement that the process launcher thread
needs to be shut down before this destructor runs.

+  registered_clients_.clear();
+}
+
+void CrashDumpObserver::RegisterClient(std::unique_ptr<Client> client) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  base::AutoLock auto_lock(registered_clients_lock_);
+  registered_clients_.push_back(std::move(client));
+}
+
+void CrashDumpObserver::OnChildExit(int child_process_id,
+                                    base::ProcessHandle pid,
+                                    content::ProcessType process_type,
+                                    base::TerminationStatus termination_status,
+                                    base::android::ApplicationState app_state) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  std::vector<Client*> registered_clients_copy;
+  {
+    base::AutoLock auto_lock(registered_clients_lock_);
+    for (auto& client : registered_clients_)
+      registered_clients_copy.push_back(client.get());
+  }
+  for (auto& client : registered_clients_copy) {
+    client->OnChildExit(child_process_id, pid, process_type, termination_status,
+                        app_state);
+  }
+}
+
+void CrashDumpObserver::BrowserChildProcessStarted(
+    int child_process_id,
+    content::FileDescriptorInfo* mappings) {
+  DCHECK_CURRENTLY_ON(BrowserThread::PROCESS_LAUNCHER);
+  std::vector<Client*> registered_clients_copy;
+  {
+    base::AutoLock auto_lock(registered_clients_lock_);
+    for (auto& client : registered_clients_)
+      registered_clients_copy.push_back(client.get());
+  }
+  for (auto& client : registered_clients_copy) {
+    client->OnChildStart(child_process_id, mappings);
+  }
+}
+
+void CrashDumpObserver::BrowserChildProcessHostDisconnected(
+    const content::ChildProcessData& data) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  OnChildExit(data.id, data.handle,
+              static_cast<content::ProcessType>(data.process_type),
+              base::TERMINATION_STATUS_MAX_ENUM,
+              base::android::ApplicationStatusListener::GetState());
+}
+
+void CrashDumpObserver::BrowserChildProcessCrashed(
+    const content::ChildProcessData& data,
+    int exit_code) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  OnChildExit(data.id, data.handle,
+              static_cast<content::ProcessType>(data.process_type),
+              base::TERMINATION_STATUS_ABNORMAL_TERMINATION,
+              base::android::APPLICATION_STATE_UNKNOWN);
+}
+
+void CrashDumpObserver::Observe(int type,
+                                const content::NotificationSource& source,
+                                const content::NotificationDetails& details) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  content::RenderProcessHost* rph =
+      content::Source<content::RenderProcessHost>(source).ptr();
+  base::TerminationStatus term_status = base::TERMINATION_STATUS_MAX_ENUM;
+  base::android::ApplicationState app_state =
+      base::android::APPLICATION_STATE_UNKNOWN;
+  switch (type) {
+    case content::NOTIFICATION_RENDERER_PROCESS_TERMINATED: {
+      // NOTIFICATION_RENDERER_PROCESS_TERMINATED is sent when the renderer
+      // process is cleanly shutdown.
+      term_status = base::TERMINATION_STATUS_NORMAL_TERMINATION;
+      break;
+    }
+    case content::NOTIFICATION_RENDERER_PROCESS_CLOSED: {
+      // We do not care about android fast shutdowns as it is a known case where
+      // the renderer is intentionally killed when we are done with it.
+      if (rph->FastShutdownStarted()) {
+        break;
+      }
+      content::RenderProcessHost::RendererClosedDetails* process_details =
+          content::Details<content::RenderProcessHost::RendererClosedDetails>(
+              details)
+              .ptr();
+      term_status = process_details->status;
+      app_state = base::android::ApplicationStatusListener::GetState();
+      break;
+    }
+    default:
+      NOTREACHED();
+      return;
+  }
+
+  OnChildExit(rph->GetID(), rph->GetHandle(), content::PROCESS_TYPE_RENDERER,
+              term_status, app_state);
+}
+
+}  // namespace breakpad