Add a "Simplify Page" option to the print preview dialog

chrome/browser/ui/webui/print_preview/hidden_print_preview.cc

Index: chrome/browser/ui/webui/print_preview/hidden_print_preview.cc
diff --git a/chrome/browser/ui/webui/print_preview/hidden_print_preview.cc b/chrome/browser/ui/webui/print_preview/hidden_print_preview.cc
new file mode 100644
index 0000000000000000000000000000000000000000..176f22bc971802ac450f86bc0977f360ea3d9827
--- /dev/null
+++ b/chrome/browser/ui/webui/print_preview/hidden_print_preview.cc
@@ -0,0 +1,297 @@
+// Copyright (c) 2015 The Chromium Authors. All rights reserved.

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:31]

 we use "// Copyright 2015" now

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/ui/webui/print_preview/hidden_print_preview.h"
+
+#include <string>
+
+#include "base/strings/utf_string_conversions.h"
+#include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/dom_distiller/tab_utils.h"
+#include "chrome/browser/printing/print_preview_dialog_controller.h"
+#include "chrome/browser/printing/print_preview_message_handler.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/tab_helpers.h"
+#include "chrome/browser/ui/web_contents_sizer.h"
+#include "chrome/browser/ui/webui/print_preview/print_preview_ui.h"
+#include "chrome/common/prerender_messages.h"
+#include "components/printing/common/print_messages.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/render_view_host.h"
+#include "content/public/browser/session_storage_namespace.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_delegate.h"
+
+using content::BrowserThread;
+using content::OpenURLParams;
+using content::RenderViewHost;
+using content::SessionStorageNamespace;
+using content::WebContents;
+
+class HiddenPrintPreview::WebContentsDelegateImpl
+    : public content::WebContentsDelegate {
+ public:
+  explicit WebContentsDelegateImpl(HiddenPrintPreview* hidden_print_preview)
+      : hidden_print_preview_(hidden_print_preview) {
+  }
+
+  // content::WebContentsDelegate implementation:
+  WebContents* OpenURLFromTab(WebContents* source,
+                              const OpenURLParams& params) override {
+    // |OpenURLFromTab| is typically called when a frame performs a navigation
+    // that requires the browser to perform the transition instead of WebKit.
+    // Examples include rendering a site that redirects to an app URL,

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:30]

I am no sure how distilled web content works
is navigation there are possible at all? 

+    // or if --enable-strict-site-isolation is specified and the rendered
+    // frame redirects to a different origin.
+    hidden_print_preview_->Destroy();
+    return NULL;

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:31]

nullptr

+  }
+
+  void CloseContents(content::WebContents* contents) override {
+    hidden_print_preview_->Destroy();
+  }
+
+  void CanDownload(const GURL& url,
+                   const std::string& request_method,
+                   const base::Callback<void(bool)>& callback) override {
+    hidden_print_preview_->Destroy();
+    // Cancel the download.
+    callback.Run(false);
+  }
+
+  bool ShouldCreateWebContents(
+      WebContents* web_contents,
+      int route_id,
+      int main_frame_route_id,
+      WindowContainerType window_container_type,
+      const base::string16& frame_name,
+      const GURL& target_url,
+      const std::string& partition_id,
+      SessionStorageNamespace* session_storage_namespace) override {
+    // Since we don't want to permit child windows that would have a
+    // window.opener property, terminate rendering.
+    hidden_print_preview_->Destroy();
+    // Cancel the popup.
+    return false;
+  }
+
+  bool OnGoToEntryOffset(int offset) override {
+    // This isn't allowed because the history merge operation
+    // does not work if there are renderer issued challenges.
+    // TODO(cbentzel): Cancel in this case? May not need to do
+    // since render-issued offset navigations are not guaranteed,
+    // but indicates that the page cares about the history.
+    return false;
+  }
+
+  bool ShouldSuppressDialogs(WebContents* source) override {
+    // We still want to show the user the message when they navigate to this
+    // page, so cancel this render.
+    hidden_print_preview_->Destroy();
+    // Always suppress JavaScript messages if they're triggered by a page being
+    // rendered.
+    return true;
+  }
+
+  void RegisterProtocolHandler(WebContents* web_contents,
+                               const std::string& protocol,
+                               const GURL& url,
+                               bool user_gesture) override {
+    hidden_print_preview_->Destroy();
+  }
+
+  gfx::Size GetSizeForNewRenderView(WebContents* web_contents) const override {
+    // Have to set the size of the RenderView on initialization to be sure it is
+    // set before the RenderView is hidden on all platforms (esp. Android).
+    return hidden_print_preview_->size_;
+  }
+
+ private:
+  HiddenPrintPreview* hidden_print_preview_;
+};
+
+HiddenPrintPreview::HiddenPrintPreview(
+    WebContents* target_web_contents,
+    PrintPreviewUI* print_preview_ui,
+    scoped_ptr<base::DictionaryValue> settings)
+    : session_storage_namespace_id_(-1),

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:31]

session_storage_namespace_id_ is not used

+      profile_(Profile::FromBrowserContext(

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:30]

don't need profile_ member, you can call FromBrowserContext when needed

+        target_web_contents->GetBrowserContext())),
+      target_web_contents_(target_web_contents),

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:31]

target_web_contents -> source_web_contents

+      settings_(settings.release()),
+      print_preview_ui_(print_preview_ui) {
+  content::SessionStorageNamespace* session_storage_namespace =
+      target_web_contents_->GetController().GetDefaultSessionStorageNamespace();
+  StartRendering(gfx::Size(1, 1), session_storage_namespace);
+
+  DCHECK(web_contents_);
+  ::DistillAndView(target_web_contents_, web_contents_.get());
+}
+
+void HiddenPrintPreview::StartRendering(

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:30]

StartRendering starts nothing.
Probably should be called CreateDestinationWebContents

+    const gfx::Size& size,
+    SessionStorageNamespace* session_storage_namespace) {
+  DCHECK(profile_ != NULL);
+  DCHECK(!size.IsEmpty());
+  DCHECK(web_contents_.get() == NULL);
+  DCHECK(size_.IsEmpty());
+
+  session_storage_namespace_id_ = session_storage_namespace->id();
+  size_ = size;
+
+  web_contents_.reset(CreateWebContents(session_storage_namespace));
+  TabHelpers::AttachTabHelpers(web_contents_.get());
+  content::WebContentsObserver::Observe(web_contents_.get());
+
+  web_contents_delegate_.reset(new WebContentsDelegateImpl(this));
+  web_contents_.get()->SetDelegate(web_contents_delegate_.get());

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:31]

maybe better to set/remove delgate in constructor/destructor of
WebContentsDelegateImpl

+
+  // Set the size of the hidden WebContents.
+  ResizeWebContents(web_contents_.get(), size_);
+
+  // Close ourselves when the application is shutting down.
+  notification_registrar_.Add(this, chrome::NOTIFICATION_APP_TERMINATING,
+                              content::NotificationService::AllSources());
+
+  // Register to inform new RenderViews that we're rendering.
+  notification_registrar_.Add(
+      this, content::NOTIFICATION_WEB_CONTENTS_RENDER_VIEW_HOST_CREATED,
+      content::Source<WebContents>(web_contents_.get()));
+}
+
+HiddenPrintPreview::~HiddenPrintPreview() {
+  if (web_contents_.get()) {

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:30]

just "if (web_contents_)" and everywhere else

+    web_contents_->SetDelegate(NULL);
+    content::WebContentsObserver::Observe(NULL);

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:30]

Probably WebContentsDelegateImpl should be a WebContentsObserver and
NotificationObserver

+
+    printing::PrintPreviewDialogController* dialog_controller =
+        printing::PrintPreviewDialogController::GetInstance();
+    if (!dialog_controller)
+      return;
+
+    dialog_controller->RemoveProxyDialogForWebContents(web_contents_.get());
+  }
+}
+
+void HiddenPrintPreview::Observe(int type,
+                                const content::NotificationSource& source,
+                                const content::NotificationDetails& details) {
+  switch (type) {
+    // TODO(davidben): Try to remove this in favor of relying on
+    // FINAL_STATUS_PROFILE_DESTROYED.
+    case chrome::NOTIFICATION_APP_TERMINATING:
+      Destroy();
+      return;
+
+    case content::NOTIFICATION_WEB_CONTENTS_RENDER_VIEW_HOST_CREATED: {
+      if (web_contents_.get()) {
+        DCHECK_EQ(content::Source<WebContents>(source).ptr(),
+                  web_contents_.get());
+
+        // Make sure the size of the RenderViewHost has been passed to the new
+        // RenderView.  Otherwise, the size may not be sent until the
+        // RenderViewReady event makes it from the render process to the UI
+        // thread of the browser process.  When the RenderView receives its
+        // size, is also sets itself to be visible, which would then break the
+        // visibility API.
+        content::Details<RenderViewHost> new_render_view_host(details);
+        new_render_view_host->WasResized();
+        web_contents_->WasHidden();
+      }
+      break;
+    }
+
+    default:
+      NOTREACHED() << "Unexpected notification sent.";
+      break;
+  }
+}
+
+WebContents* HiddenPrintPreview::CreateWebContents(
+    SessionStorageNamespace* session_storage_namespace) {
+  // TODO(ajwong): Remove the temporary map once prerendering is aware of
+  // multiple session storage namespaces per tab.
+  content::SessionStorageNamespaceMap session_storage_namespace_map;
+  session_storage_namespace_map[std::string()] = session_storage_namespace;
+  return WebContents::CreateWithSessionStorage(
+      WebContents::CreateParams(profile_), session_storage_namespace_map);
+}
+
+void HiddenPrintPreview::RenderProcessGone(base::TerminationStatus status) {
+  Destroy();
+}
+
+void HiddenPrintPreview::RenderFrameCreated(
+    content::RenderFrameHost* render_frame_host) {
+  // When a new RenderFrame is created for a hidden rendering WebContents, tell
+  // the new RenderFrame it's being used for prerendering before any
+  // navigations occur.  Note that this is always triggered before the first
+  // navigation, so there's no need to send the message just after the
+  // WebContents is created.
+  render_frame_host->Send(new PrerenderMsg_SetIsPrerendering(
+      render_frame_host->GetRoutingID(), true));
+}
+
+void HiddenPrintPreview::DidStopLoading() {

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:30]

Please remove these three. base class already has them empty.

+}
+
+void HiddenPrintPreview::DocumentLoadedInFrame(
+    content::RenderFrameHost* render_frame_host) {
+}
+
+void HiddenPrintPreview::DidStartProvisionalLoadForFrame(
+    content::RenderFrameHost* render_frame_host,
+    const GURL& validated_url,
+    bool is_error_page,
+    bool is_iframe_srcdoc) {
+}
+
+void HiddenPrintPreview::DidFinishLoad(
+    content::RenderFrameHost* render_frame_host,
+    const GURL& validated_url) {
+  // Ask the page to trigger an anchor navigation once the distilled
+  // contents are added to the page.
+  web_contents()->GetMainFrame()->ExecuteJavaScript(
+          base::UTF8ToUTF16("setNavigateOnInitialContentLoad(true);"));
+}
+
+void HiddenPrintPreview::DidNavigateMainFrame(
+    const content::LoadCommittedDetails& details,
+    const content::FrameNavigateParams& params) {
+  // The second content loads signals that the distilled contents have
+  // been delivered to the page via inline JavaScript execution.
+  if (web_contents_->GetController().GetEntryCount() > 1) {
+    DCHECK(web_contents_);
+
+    printing::PrintPreviewDialogController* dialog_controller =
+        printing::PrintPreviewDialogController::GetInstance();
+    if (!dialog_controller) {
+      return;
+    }
+    dialog_controller->AddProxyDialogForWebContents(

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:30]

why Add here and not when contents created?

+      web_contents_.get(), target_web_contents_);
+
+    DCHECK(settings_);
+    RenderViewHost* rvh = web_contents_->GetRenderViewHost();
+    rvh->Send(new PrintMsg_InitiatePrintPreview(rvh->GetRoutingID(), false));
+    rvh->Send(new PrintMsg_PrintPreview(rvh->GetRoutingID(), *settings_));
+  }
+}
+
+void HiddenPrintPreview::DidGetRedirectForResourceRequest(
+    content::RenderFrameHost* render_frame_host,
+    const content::ResourceRedirectDetails& details) {
+    // Redirects are unsupported for hidden renderers.
+    Destroy();
+}
+
+void HiddenPrintPreview::Destroy() {

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:30]

Destroy -> Fail or Abort

+  if (rendering_has_been_cancelled_)

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:30]

I don't see who change rendering_has_been_cancelled_

+    return;
+
+  print_preview_ui_->OnPrintPreviewFailed();

[Vitaly Buka (NO REVIEWS), 2015/07/13 07:00:30]

I don't see other use of print_preview_ui_ here
Can you replace with on_failed_callback_

+}