[ios] Convert BlockedPopupHandler into a tab helper class.

ios/chrome/browser/web/blocked_popup_tab_helper.mm

Index: ios/chrome/browser/web/blocked_popup_tab_helper.mm
diff --git a/ios/chrome/browser/web/blocked_popup_handler.mm b/ios/chrome/browser/web/blocked_popup_tab_helper.mm
similarity index 71%
rename from ios/chrome/browser/web/blocked_popup_handler.mm
rename to ios/chrome/browser/web/blocked_popup_tab_helper.mm
index 40c6b71212cced9327d62f0164fdc50de0c0997d..1723a22feb82e43fad231db8ae77185588ccf249 100644
--- a/ios/chrome/browser/web/blocked_popup_handler.mm
+++ b/ios/chrome/browser/web/blocked_popup_tab_helper.mm
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#import "ios/chrome/browser/web/blocked_popup_handler.h"
+#import "ios/chrome/browser/web/blocked_popup_tab_helper.h"
 
 #include <memory>
 #include <utility>
@@ -17,12 +17,15 @@
 #include "components/infobars/core/infobar.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/content_settings/host_content_settings_map_factory.h"
+#include "ios/chrome/browser/infobars/infobar_manager_impl.h"
 #include "ios/chrome/grit/ios_strings.h"
 #include "ios/web/public/referrer.h"
 #include "net/base/mac/url_conversions.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/image/image.h"
 
+DEFINE_WEB_STATE_USER_DATA_KEY(BlockedPopupTabHelper);
+
 namespace {
 // The infobar to display when a popup is blocked.
 class BlockPopupInfoBarDelegate : public ConfirmInfoBarDelegate {
@@ -85,55 +88,61 @@ class BlockPopupInfoBarDelegate : public ConfirmInfoBarDelegate {
 };
 }  // namespace
 
-BlockedPopupHandler::BlockedPopupHandler(ios::ChromeBrowserState* browser_state)
-    : browser_state_(browser_state),
-      delegate_(nullptr),
-      infobar_(nullptr),
-      scoped_observer_(this) {}
-
-BlockedPopupHandler::~BlockedPopupHandler() {}
+BlockedPopupTabHelper::BlockedPopupTabHelper(web::WebState* web_state)
+    : web_state_(web_state), infobar_(nullptr), scoped_observer_(this) {}
 
-void BlockedPopupHandler::SetDelegate(
-    id<BlockedPopupHandlerDelegate> delegate) {
-  scoped_observer_.RemoveAll();
-  delegate_ = delegate;
-  if (delegate_)
-    scoped_observer_.Add([delegate_ infoBarManager]);
-}
+BlockedPopupTabHelper::~BlockedPopupTabHelper() {}

[Eugene But (OOO till 7-30), 2017/01/17 22:10:21]

nit: 

BlockedPopupTabHelper::~BlockedPopupTabHelper() = default;

[rohitrao (ping after 24h), 2017/01/23 15:30:29]

Is it better to use default rather than {}?

 
-void BlockedPopupHandler::HandlePopup(
+void BlockedPopupTabHelper::HandlePopup(
     const web::BlockedPopupInfo& blocked_popup_info) {
-  if (!delegate_)
-    return;
-
   popups_.push_back(blocked_popup_info);
   ShowInfoBar();
 }
 
-void BlockedPopupHandler::OnInfoBarRemoved(infobars::InfoBar* infobar,
-                                           bool animate) {
+void BlockedPopupTabHelper::OnInfoBarRemoved(infobars::InfoBar* infobar,
+                                             bool animate) {
   if (infobar == infobar_) {
     infobar_ = nullptr;
     popups_.clear();

[sdefresne, 2017/01/18 10:20:56]

nit: you can stop observing at that point, can't you?

  popups_.clear();
  scoped_observer_.RemoveAll();

[rohitrao (ping after 24h), 2017/01/23 15:30:29]

Done.

   }
 }
 
-void BlockedPopupHandler::OnManagerShuttingDown(
+void BlockedPopupTabHelper::OnManagerShuttingDown(
     infobars::InfoBarManager* infobar_manager) {
   scoped_observer_.Remove(infobar_manager);
 }
 
-void BlockedPopupHandler::ShowInfoBar() {
-  if (!popups_.size() || !delegate_)
+void BlockedPopupTabHelper::ShowInfoBar() {
+  infobars::InfoBarManager* infobar_manager =
+      InfoBarManagerImpl::FromWebState(web_state_);
+  if (!popups_.size() || !infobar_manager)
     return;
-  infobars::InfoBarManager* infobar_manager = [delegate_ infoBarManager];
+
+  RegisterAsInfoBarManagerObserverIfNeeded();

[sdefresne, 2017/01/18 10:20:57]

nit: maybe pass the infobar manager as parameter (since the method access it
again as first thing)

[rohitrao (ping after 24h), 2017/01/23 15:30:29]

Done.

+
+  ios::ChromeBrowserState* browser_state =
+      ios::ChromeBrowserState::FromBrowserState(web_state_->GetBrowserState());
   std::unique_ptr<infobars::InfoBar> infobar =
       infobar_manager->CreateConfirmInfoBar(
           std::unique_ptr<ConfirmInfoBarDelegate>(

[sdefresne, 2017/01/18 10:20:57]

nit: I think you can use base::MakeUnique here

  std::unique_ptr<infobars::InfoBar> infobar =
      infobar_manager->CreateConfirmInfoBar(
          base::MakeUnique<BlockPopupInfoBarDelegate>(
              browser_state, popups_));

[rohitrao (ping after 24h), 2017/01/23 15:30:29]

Done.

-              new BlockPopupInfoBarDelegate(browser_state_, popups_)));
+              new BlockPopupInfoBarDelegate(browser_state, popups_)));
   if (infobar_) {
     infobar_ = infobar_manager->ReplaceInfoBar(infobar_, std::move(infobar));
   } else {
     infobar_ = infobar_manager->AddInfoBar(std::move(infobar));
   }
 }
+
+void BlockedPopupTabHelper::RegisterAsInfoBarManagerObserverIfNeeded() {
+  infobars::InfoBarManager* manager =
+      InfoBarManagerImpl::FromWebState(web_state_);
+  DCHECK(manager);
+
+  if (scoped_observer_.IsObserving(manager)) {
+    return;
+  }
+
+  // Verify that this object is never observing more than one InfoBarManager.
+  DCHECK(!scoped_observer_.IsObservingSources());
+  scoped_observer_.Add(manager);
+}