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

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

Index: chrome/browser/ui/webui/print_preview/hidden_web_contents.cc
diff --git a/chrome/browser/ui/webui/print_preview/hidden_web_contents.cc b/chrome/browser/ui/webui/print_preview/hidden_web_contents.cc
new file mode 100644
index 0000000000000000000000000000000000000000..246b22bf73e35f80141f287182855a62e147d5b4
--- /dev/null
+++ b/chrome/browser/ui/webui/print_preview/hidden_web_contents.cc
@@ -0,0 +1,324 @@
+// Copyright (c) 2014 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/ui/webui/print_preview/hidden_web_contents.h"
+
+#include <string>
+
+#include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/tab_helpers.h"
+#include "chrome/browser/ui/web_contents_sizer.h"
+#include "chrome/common/prerender_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::OpenURLParams;
+using content::RenderViewHost;
+using content::SessionStorageNamespace;
+using content::WebContents;
+
+class HiddenWebContents::WebContentsDelegateImpl
+    : public content::WebContentsDelegate {
+ public:
+  explicit WebContentsDelegateImpl(HiddenWebContents* hidden_web_contents)
+      : hidden_web_contents_(hidden_web_contents) {
+  }
+
+  // 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,
+    // or if --enable-strict-site-isolation is specified and the rendered
+    // frame redirects to a different origin.
+    hidden_web_contents_->Destroy();
+    return NULL;
+  }
+
+  void CloseContents(content::WebContents* contents) override {
+    hidden_web_contents_->Destroy();
+  }
+
+  void CanDownload(RenderViewHost* render_view_host,
+                   const GURL& url,
+                   const std::string& request_method,
+                   const base::Callback<void(bool)>& callback) override {
+    hidden_web_contents_->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_web_contents_->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_web_contents_->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_web_contents_->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_web_contents_->size_;
+  }
+
+ private:
+  HiddenWebContents* hidden_web_contents_;
+};
+
+void HiddenWebContents::Observer::OnFinishedLoad(
+    HiddenWebContents* contents) {
+}
+
+HiddenWebContents::Observer::Observer() {
+}
+
+HiddenWebContents::Observer::~Observer() {
+}
+
+HiddenWebContents::HiddenWebContents(
+    Profile* profile,
+    const GURL& url)
+    : rendering_has_started_(false),
+      session_storage_namespace_id_(-1),
+      url_(url),
+      profile_(profile),
+      has_stopped_loading_(false),
+      has_finished_loading_(false),
+      rendering_has_been_cancelled_(false) {
+}
+
+// static
+bool HiddenWebContents::IsValidUrl(const GURL& url) {
+  return url.SchemeIs("chrome-distiller");
+}
+
+void HiddenWebContents::StartRendering(
+    const gfx::Size& size,
+    SessionStorageNamespace* session_storage_namespace) {
+  DCHECK(profile_ != NULL);
+  DCHECK(!size.IsEmpty());
+  DCHECK(!rendering_has_started_);
+  DCHECK(web_contents_.get() == NULL);
+  DCHECK(size_.IsEmpty());
+
+  if (!HiddenWebContents::IsValidUrl(url_)) {
+    Destroy();
+    return;
+  }
+
+  session_storage_namespace_id_ = session_storage_namespace->id();
+  size_ = size;
+
+  rendering_has_started_ = true;
+
+  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());
+
+  // 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()));
+
+  content::NavigationController::LoadURLParams load_url_params(url_);
+  load_url_params.transition_type = ui::PAGE_TRANSITION_LINK;
+  web_contents_.get()->GetController().LoadURLWithParams(load_url_params);
+}
+
+HiddenWebContents::~HiddenWebContents() {
+  if (web_contents_.get()) {
+      web_contents_->SetDelegate(NULL);
+      content::WebContentsObserver::Observe(NULL);
+  }
+}
+
+void HiddenWebContents::AddObserver(Observer* observer) {
+  observer_list_.AddObserver(observer);
+}
+
+void HiddenWebContents::RemoveObserver(Observer* observer) {
+  observer_list_.RemoveObserver(observer);
+}
+
+void HiddenWebContents::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* HiddenWebContents::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 HiddenWebContents::NotifyFail() {
+  FOR_EACH_OBSERVER(Observer, observer_list_, OnFail(this));
+  observer_list_.Clear();
+}
+
+void HiddenWebContents::NotifyFinishedLoad() {
+  FOR_EACH_OBSERVER(Observer, observer_list_, OnFinishedLoad(this));
+}
+
+void HiddenWebContents::RenderProcessGone(base::TerminationStatus status) {
+  Destroy();
+}
+
+void HiddenWebContents::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 HiddenWebContents::DidStopLoading() {
+  has_stopped_loading_ = true;
+}
+
+void HiddenWebContents::DocumentLoadedInFrame(
+    content::RenderFrameHost* render_frame_host) {
+}
+
+void HiddenWebContents::DidStartProvisionalLoadForFrame(
+    content::RenderFrameHost* render_frame_host,
+    const GURL& validated_url,
+    bool is_error_page,
+    bool is_iframe_srcdoc) {
+  if (!render_frame_host->GetParent()) {
+    // Usually, this event fires if the user clicks or enters a new URL.
+    // Neither of these can happen in the case of an hidden renderer.
+    // So the cause is: Some JavaScript caused a new URL to be loaded.  In that
+    // case, the spinner would start again in the browser, so we must reset
+    // has_stopped_loading_ so that the spinner won't be stopped.
+    has_stopped_loading_ = false;
+    has_finished_loading_ = false;
+  }
+}
+
+void HiddenWebContents::DidFinishLoad(
+    content::RenderFrameHost* render_frame_host,
+    const GURL& validated_url) {
+  if (!render_frame_host->GetParent())
+    has_finished_loading_ = true;
+  NotifyFinishedLoad();
+}
+
+void HiddenWebContents::DidNavigateMainFrame(
+    const content::LoadCommittedDetails& details,
+    const content::FrameNavigateParams& params) {
+  // If the render made a second navigation entry, abort the render. This
+  // avoids having to correctly implement a complex history merging case (this
+  // interacts with location.replace) and correctly synchronize with the
+  // renderer. The final status may be monitored to see we need to revisit this
+  // decision. This does not affect client redirects as those do not push new
+  // history entries. (Calls to location.replace, navigations before onload, and
+  // <meta http-equiv=refresh> with timeouts under 1 second do not create
+  // entries in Blink.)
+  if (web_contents_->GetController().GetEntryCount() > 1)
+    Destroy();
+}
+
+void HiddenWebContents::DidGetRedirectForResourceRequest(
+    content::RenderFrameHost* render_frame_host,
+    const content::ResourceRedirectDetails& details) {
+    // Redirects are unsupported for hidden renderers.
+    Destroy();
+}
+
+void HiddenWebContents::Destroy() {
+  if (rendering_has_been_cancelled_)
+    return;
+
+  rendering_has_been_cancelled_ = true;
+  NotifyFail();
+}