Add support for distilling current WebContents

chrome/browser/ui/tab_helpers.cc

 // Copyright 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/tab_helpers.h"
 
 #include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/content_settings/tab_specific_content_settings.h"
 #include "chrome/browser/extensions/tab_helper.h"
@@ skipping 11 matching lines @@
 #include "chrome/browser/ui/blocked_content/popup_blocker_tab_helper.h"
 #include "chrome/browser/ui/bookmarks/bookmark_tab_helper.h"
 #include "chrome/browser/ui/find_bar/find_tab_helper.h"
 #include "chrome/browser/ui/navigation_correction_tab_observer.h"
 #include "chrome/browser/ui/prefs/prefs_tab_helper.h"
 #include "chrome/browser/ui/search/search_tab_helper.h"
 #include "chrome/browser/ui/tab_contents/core_tab_helper.h"
 #include "chrome/common/chrome_switches.h"
 #include "components/autofill/content/browser/content_autofill_driver.h"
 #include "components/autofill/core/browser/autofill_manager.h"
+#include "components/dom_distiller/content/web_contents_main_frame_observer.h"
 #include "components/password_manager/core/browser/password_manager.h"
 #include "content/public/browser/web_contents.h"
 #include "extensions/browser/view_type_utils.h"
 
 #if defined(OS_ANDROID)
 #include "chrome/browser/android/webapps/single_tab_mode_tab_helper.h"
 #include "chrome/browser/ui/android/context_menu_helper.h"
 #include "chrome/browser/ui/android/window_android_helper.h"
 #else
 #include "chrome/browser/extensions/api/web_navigation/web_navigation_api.h"
@@ skipping 142 matching lines @@
 
 #if defined(ENABLE_PRINTING) && !defined(OS_ANDROID)
 #if defined(ENABLE_FULL_PRINTING)
   printing::PrintViewManager::CreateForWebContents(web_contents);
   printing::PrintPreviewMessageHandler::CreateForWebContents(web_contents);
 #else
   printing::PrintViewManagerBasic::CreateForWebContents(web_contents);
 #endif  // defined(ENABLE_FULL_PRINTING)
 #endif  // defined(ENABLE_PRINTING) && !defined(OS_ANDROID)
 
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableDomDistiller)) {
+    dom_distiller::WebContentsMainFrameObserver::CreateForWebContents(

[sky, 2014/05/20 20:59:45]

Why do we need to do this here? Can't you install whatever is needed when the
menu item is clicked?

[nyquist, 2014/05/20 21:03:28]

The WebContentsMainFrameObserver is only there to track whether the
WebContentsObservers of the given |web_contents| have gotten a call to
DocumentLoadedInFrame for the main frame. Adding it at the time of when you
click the menu item would be too late, as the event has most probably already
been triggered. Say you go to a page, click the menu item, and then add the
observer; chances are the page has already (at least mostly) loaded.

After talking to jam@ I realized that putting this state tracking in //content
was not encouraged, if it was possible to do it in //chrome.

[sky, 2014/05/20 23:25:20]

Can't you determine what you need at the time you need it rather than making
everything get more expensive in anticipation of using something?

[nyquist, 2014/05/20 23:28:11]

That would be great, but I could not find any place where this state is already
stored. In WebContents / WebContentsImpl, the events are just forwarded to the
observers. Any thoughts as to where this could already be?

+        web_contents);
+  }
+
 #if defined(ENABLE_ONE_CLICK_SIGNIN)
   // If this is not an incognito window, setup to handle one-click login.
   // We don't want to check that the profile is already connected at this time
   // because the connected state may change while this tab is open.  Having a
   // one-click signin helper attached does not cause problems if the profile
   // happens to be already connected.
   if (OneClickSigninHelper::CanOffer(web_contents,
                                      OneClickSigninHelper::CAN_OFFER_FOR_ALL,
                                      std::string(),
                                      NULL)) {
     OneClickSigninHelper::CreateForWebContentsWithPasswordManager(
         web_contents,
         ChromePasswordManagerClient::GetManagerFromWebContents(web_contents));
   }
 #endif
 }