Add PreviewsInfoBarTabHelper

PreviewsInfoBarTabHelper tracks whether a previews infobar
has been shown for a tab. If a previews infobar has already
been shown for a tab, it will not be shown again.

BUG=615566

Review-Url: https://codereview.chromium.org/2256383002
Cr-Commit-Position: refs/heads/master@{#418588}

chrome/browser/BUILD.gn

@@ -876,6 +876,8 @@ split_static_library("browser") {
     "prerender/prerender_util.h",
     "previews/previews_infobar_delegate.cc",
     "previews/previews_infobar_delegate.h",
+    "previews/previews_infobar_tab_helper.cc",
+    "previews/previews_infobar_tab_helper.h",
     "previews/previews_service.cc",
     "previews/previews_service.h",
     "previews/previews_service_factory.cc",

chrome/browser/previews/previews_infobar_delegate.cc

@@ -8,6 +8,7 @@
 #include "chrome/browser/infobars/infobar_service.h"
 #include "chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.h"
 #include "chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings_factory.h"
+#include "chrome/browser/previews/previews_infobar_tab_helper.h"
 #include "chrome/grit/generated_resources.h"
 #include "components/infobars/core/infobar.h"
 #include "content/public/browser/render_frame_host.h"
@@ -19,7 +20,10 @@ PreviewsInfoBarDelegate::~PreviewsInfoBarDelegate() {}
 // static
 void PreviewsInfoBarDelegate::Create(content::WebContents* web_contents,
                                      PreviewsInfoBarType infobar_type) {
-  // TODO(megjablon): Check that the infobar was not already shown.
+  PreviewsInfoBarTabHelper* infobar_tab_helper =
+      PreviewsInfoBarTabHelper::FromWebContents(web_contents);
+  if (infobar_tab_helper->displayed_preview_infobar())
+    return;
 
   InfoBarService* infobar_service =
       InfoBarService::FromWebContents(web_contents);
@@ -35,6 +39,8 @@ void PreviewsInfoBarDelegate::Create(content::WebContents* web_contents,
             web_contents->GetBrowserContext());
     data_reduction_proxy_settings->IncrementLoFiUIShown();
   }
+
+  infobar_tab_helper->set_displayed_preview_infobar(true);
 }
 
 PreviewsInfoBarDelegate::PreviewsInfoBarDelegate(

chrome/browser/previews/previews_infobar_tab_helper.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 "chrome/browser/previews/previews_infobar_tab_helper.h"
+
+#include "chrome/browser/previews/previews_infobar_delegate.h"
+#include "components/data_reduction_proxy/core/common/data_reduction_proxy_headers.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/navigation_handle.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/web_contents.h"
+#include "net/http/http_response_headers.h"
+#include "url/gurl.h"
+
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(PreviewsInfoBarTabHelper);
+
+PreviewsInfoBarTabHelper::~PreviewsInfoBarTabHelper() {}
+
+PreviewsInfoBarTabHelper::PreviewsInfoBarTabHelper(
+    content::WebContents* web_contents)
+    : content::WebContentsObserver(web_contents),
+      displayed_preview_infobar_(false) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+}
+
+void PreviewsInfoBarTabHelper::DidStartProvisionalLoadForFrame(
+    content::RenderFrameHost* render_frame_host,
+    const GURL& validated_url,
+    bool is_error_page,
+    bool is_iframe_srcdoc) {
+  if (!render_frame_host->GetParent())
+    set_displayed_preview_infobar(false);
+}
+
+void PreviewsInfoBarTabHelper::DidFinishNavigation(
+    content::NavigationHandle* navigation_handle) {
+  if (!navigation_handle->IsInMainFrame() || !navigation_handle->HasCommitted())
+    return;
+  const net::HttpResponseHeaders* headers =
+      navigation_handle->GetResponseHeaders();
+  if (headers &&
+      headers->HasHeaderValue(
+          data_reduction_proxy::chrome_proxy_header(),
+          data_reduction_proxy::chrome_proxy_lo_fi_preview_directive())) {
+    PreviewsInfoBarDelegate::Create(navigation_handle->GetWebContents(),
+                                    PreviewsInfoBarDelegate::LITE_PAGE);
+  }
+}
+

chrome/browser/previews/previews_infobar_tab_helper.h

+// 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.
+
+#ifndef CHROME_BROWSER_PREVIEWS_PREVIEWS_INFOBAR_TAB_HELPER_H_
+#define CHROME_BROWSER_PREVIEWS_PREVIEWS_INFOBAR_TAB_HELPER_H_
+
+#include "base/macros.h"
+#include "content/public/browser/web_contents_observer.h"
+#include "content/public/browser/web_contents_user_data.h"
+
+class GURL;
+
+namespace content {
+class RenderFrameHost;
+}
+
+// Tracks whether a previews infobar has been shown for a page. Handles showing
+// the infobar when the main frame response indicates a Lite Page.
+class PreviewsInfoBarTabHelper
+    : public content::WebContentsObserver,
+      public content::WebContentsUserData<PreviewsInfoBarTabHelper> {
+ public:
+  ~PreviewsInfoBarTabHelper() override;
+
+  // Indicates whether the InfoBar for a preview has been shown for the page.
+  bool displayed_preview_infobar() const {
+    return displayed_preview_infobar_;
+  }
+
+  // Sets whether the InfoBar for a preview has been shown for the page.
+  // |displayed_preview_infobar_| is reset to false on
+  // DidStartProvisionalLoadForFrame for the main frame.
+  void set_displayed_preview_infobar(bool displayed) {
+    displayed_preview_infobar_ = displayed;
+  }
+
+ private:
+  friend class content::WebContentsUserData<PreviewsInfoBarTabHelper>;
+
+  explicit PreviewsInfoBarTabHelper(content::WebContents* web_contents);
+
+  // Overridden from content::WebContentsObserver:
+  void DidStartProvisionalLoadForFrame(
+      content::RenderFrameHost* render_frame_host,
+      const GURL& validated_url,
+      bool is_error_page,
+      bool is_iframe_srcdoc) override;
+  void DidFinishNavigation(
+      content::NavigationHandle* navigation_handle) override;
+
+  // True if the InfoBar for a preview has been shown for the page.
+  bool displayed_preview_infobar_;
+
+  DISALLOW_COPY_AND_ASSIGN(PreviewsInfoBarTabHelper);
+};
+
+#endif  // CHROME_BROWSER_PREVIEWS_PREVIEWS_INFOBAR_TAB_HELPER_H_

chrome/browser/ui/tab_helpers.cc

@@ -29,6 +29,7 @@
 #include "chrome/browser/predictors/resource_prefetch_predictor_factory.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor_tab_helper.h"
 #include "chrome/browser/prerender/prerender_tab_helper.h"
+#include "chrome/browser/previews/previews_infobar_tab_helper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sessions/session_tab_helper.h"
 #include "chrome/browser/ssl/chrome_security_state_model_client.h"
@@ -184,6 +185,7 @@ void TabHelpers::AttachTabHelpers(WebContents* web_contents) {
   PopupBlockerTabHelper::CreateForWebContents(web_contents);
   PrefsTabHelper::CreateForWebContents(web_contents);
   prerender::PrerenderTabHelper::CreateForWebContents(web_contents);
+  PreviewsInfoBarTabHelper::CreateForWebContents(web_contents);
   SearchTabHelper::CreateForWebContents(web_contents);
   ChromeSecurityStateModelClient::CreateForWebContents(web_contents);
   if (SiteEngagementService::IsEnabled())