[Android] Add support for a hung renderer dialog

chrome/browser/android/hung_renderer_infobar_delegate.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/android/hung_renderer_infobar_delegate.h"
+
+#include "base/callback.h"
+#include "base/metrics/histogram.h"
+#include "chrome/browser/infobars/infobar_service.h"
+#include "chrome/grit/generated_resources.h"
+#include "components/infobars/core/infobar.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/common/result_codes.h"
+#include "grit/theme_resources.h"
+#include "ui/base/l10n/l10n_util.h"
+
+// static
+void HungRendererInfoBarDelegate::Create(content::WebContents* web_contents) {
+  DCHECK(web_contents);
+  InfoBarService* infobar_service =
+      InfoBarService::FromWebContents(web_contents);
+  if (!infobar_service)
+    return;

[Peter Kasting, 2015/09/02 21:52:45]

The only caller of this method has already assumed the infobar service pointer
is valid, so you don't need this conditional.

[jdduke (slow), 2015/09/02 23:00:35]

Done.

+  scoped_ptr<ConfirmInfoBarDelegate> delegate(
+      new HungRendererInfoBarDelegate(web_contents));

[Peter Kasting, 2015/09/02 21:52:45]

Nit: You can avoid the Pass() call and the temp here by inlining this into the
next statement, which is what most Create() implementations do.

[jdduke (slow), 2015/09/02 23:00:35]

Done.

+  infobar_service->AddInfoBar(
+      infobar_service->CreateConfirmInfoBar(delegate.Pass()));
+}
+
+void HungRendererInfoBarDelegate::OnRendererResponsive() {
+  LogEvent(RENDERER_BECAME_RESPONSIVE);
+}
+
+HungRendererInfoBarDelegate::HungRendererInfoBarDelegate(
+    content::WebContents* web_contents)
+    : web_contents_(web_contents), terminal_event_logged_for_uma_(false) {

[Peter Kasting, 2015/09/02 21:52:45]

Nit: It seems like the only thing we save |web_contents_| for is to get the
render process host later.  That suggests that we should pass in the
RenderProcessHost* directly here (to minimize the dependencies of this object),
unless it's not guaranteed to be valid yet.

[jdduke (slow), 2015/09/02 23:00:35]

Done.

+  DCHECK(web_contents);
+}
+
+HungRendererInfoBarDelegate::~HungRendererInfoBarDelegate() {
+  if (!terminal_event_logged_for_uma_)
+    LogEvent(INFOBAR_SHUTDOWN);
+}
+
+void HungRendererInfoBarDelegate::InfoBarDismissed() {
+  LogEvent(CLOSE_CLICKED);
+}
+
+HungRendererInfoBarDelegate*
+HungRendererInfoBarDelegate::AsHungRendererInfoBarDelegate() {
+  return this;
+}
+
+int HungRendererInfoBarDelegate::GetIconID() const {
+  return IDR_INFOBAR_FROZEN_TAB;
+}
+
+base::string16 HungRendererInfoBarDelegate::GetMessageText() const {
+  return l10n_util::GetPluralStringFUTF16(IDS_BROWSER_HANGMONITOR_RENDERER, 1);
+}
+
+base::string16 HungRendererInfoBarDelegate::GetButtonLabel(
+    InfoBarButton button) const {
+  return l10n_util::GetStringUTF16((button == BUTTON_OK)
+                                       ? IDS_BROWSER_HANGMONITOR_RENDERER_END
+                                       : IDS_BROWSER_HANGMONITOR_RENDERER_WAIT);
+}
+
+bool HungRendererInfoBarDelegate::Accept() {
+  LogEvent(KILL_CLICKED);
+  content::RenderProcessHost* process = web_contents_->GetRenderProcessHost();
+  process->Shutdown(content::RESULT_CODE_HUNG, false);
+  return true;
+}
+
+bool HungRendererInfoBarDelegate::Cancel() {
+  LogEvent(WAIT_CLICKED);
+  return true;
+}
+
+void HungRendererInfoBarDelegate::LogEvent(Event event) {
+  DCHECK(!terminal_event_logged_for_uma_);
+  terminal_event_logged_for_uma_ = true;
+  UMA_HISTOGRAM_ENUMERATION("Renderer.Hung.MobileInfoBar.UserEvent", event,
+                            EVENT_COUNT);
+}