Refactor CrashDump*Manager to use a shared CrashDumpObserver singleton.

android_webview/browser/aw_browser_terminator.cc

+// Copyright 2016 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 "android_webview/browser/aw_browser_terminator.h"
+
+#include <unistd.h>
+
+#include "android_webview/common/aw_descriptors.h"
+#include "base/bind.h"
+#include "base/logging.h"
+#include "base/stl_util.h"
+#include "base/sync_socket.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 android_webview {
+
+AwBrowserTerminator::AwBrowserTerminator() {}
+
+AwBrowserTerminator::~AwBrowserTerminator() {}
+
+void AwBrowserTerminator::OnChildStart(int child_process_id,
+                                       content::FileDescriptorInfo* mappings) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::PROCESS_LAUNCHER);
+
+  base::AutoLock auto_lock(child_process_id_to_pipe_lock_);
+  DCHECK(!ContainsKey(child_process_id_to_pipe_, child_process_id));
+
+  auto local_pipe = base::MakeUnique<base::SyncSocket>();
+  auto child_pipe = base::MakeUnique<base::SyncSocket>();
+  if (base::SyncSocket::CreatePair(local_pipe.get(), child_pipe.get())) {
+    child_process_id_to_pipe_[child_process_id] = std::move(local_pipe);
+    mappings->Transfer(kAndroidWebViewCrashSignalDescriptor,
+                       base::ScopedFD(dup(child_pipe->handle())));
+  }
+}
+
+void AwBrowserTerminator::ProcessTerminationStatus(
+    std::unique_ptr<base::SyncSocket> pipe) {
+  if (pipe->Peek() >= sizeof(int)) {
+    int exit_code;
+    pipe->Receive(&exit_code, sizeof(exit_code));
+    LOG(FATAL) << "Renderer process crash detected (code " << exit_code
+               << "). Terminating browser.";
+  } else {
+    // The child process hasn't written anything into the pipe. This implies
+    // that it was terminated via SIGKILL by the low memory killer, and thus we
+    // need to perform a clean exit.
+    exit(0);
+  }
+}
+
+void AwBrowserTerminator::OnChildExit(
+    int child_process_id,
+    base::ProcessHandle pid,
+    content::ProcessType process_type,
+    base::TerminationStatus termination_status,
+    base::android::ApplicationState app_state) {
+  std::unique_ptr<base::SyncSocket> pipe;
+
+  {
+    base::AutoLock auto_lock(child_process_id_to_pipe_lock_);
+    const auto& iter = child_process_id_to_pipe_.find(child_process_id);
+    if (iter == child_process_id_to_pipe_.end()) {
+      // We might get a NOTIFICATION_RENDERER_PROCESS_TERMINATED and a
+      // NOTIFICATION_RENDERER_PROCESS_CLOSED.
+      return;
+    }
+    pipe = std::move(iter->second);
+    child_process_id_to_pipe_.erase(iter);
+  }
+  if (termination_status == base::TERMINATION_STATUS_NORMAL_TERMINATION)
+    return;
+  DCHECK(pipe->handle() != base::SyncSocket::kInvalidHandle);
+  BrowserThread::PostTask(
+      BrowserThread::FILE, FROM_HERE,
+      base::Bind(&AwBrowserTerminator::ProcessTerminationStatus,

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

Nit: Things have slightly changed in base::Bind land since your last patch set
:)

You could use base::BindOnce here now (which (a) will be The Future for this
kind of stuff and (b) has the slight advantage of not requiring the base::Passed
wrapper anymore, I think).

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

Thanks for the tip. I've left this as it is, because for the moment PostTask
won't accept a OnceCallback.

+                 base::Unretained(this), base::Passed(std::move(pipe))));
+}
+
+}  // namespace breakpad