[ios] Moves find-in-page code out of Tab and into FindTabHelper.

ios/chrome/browser/ui/browser_view_controller.mm

Index: ios/chrome/browser/ui/browser_view_controller.mm
diff --git a/ios/chrome/browser/ui/browser_view_controller.mm b/ios/chrome/browser/ui/browser_view_controller.mm
index d00a200a771871f26e12a26c8768eda31acceff9..0487e6490c666a833452e46ca59bbc5f76fe97d5 100644
--- a/ios/chrome/browser/ui/browser_view_controller.mm
+++ b/ios/chrome/browser/ui/browser_view_controller.mm
@@ -56,6 +56,7 @@
 #include "ios/chrome/browser/favicon/ios_chrome_favicon_loader_factory.h"
 #import "ios/chrome/browser/find_in_page/find_in_page_controller.h"
 #import "ios/chrome/browser/find_in_page/find_in_page_model.h"
+#import "ios/chrome/browser/find_in_page/find_tab_helper.h"
 #include "ios/chrome/browser/first_run/first_run.h"
 #import "ios/chrome/browser/geolocation/omnibox_geolocation_controller.h"
 #include "ios/chrome/browser/infobars/infobar_container_ios.h"
@@ -289,6 +290,15 @@ bool IsURLAllowedInIncognito(const GURL& url) {
 // they are added to the tab model.
 NSString* const kNativeControllerTemporaryKey = @"NativeControllerTemporaryKey";
 
+// Helper function to return the FindTabHelper for the given |tab|.  If |tab| is
+// nullptr, returns nullptr.

[marq (ping after 24h), 2017/01/31 16:02:49]

Why not just return the helper's FindInPageController or nil, since that's the
only part of the helper this class cares about? Then you can get rid of all the
null checking for the helper.

[rohitrao (ping after 24h), 2017/02/08 16:14:59]

Done.

+FindTabHelper* GetFindTabHelper(Tab* tab) {
+  if (!tab) {
+    return nullptr;
+  }
+  return FindTabHelper::FromWebState(tab.webState);

[Eugene But (OOO till 7-30), 2017/01/31 19:03:48]

Optional nit: do you want to use ternary operator here?

[rohitrao (ping after 24h), 2017/02/08 16:14:59]

Acknowledged.

+}
+
 }  // anonymous namespace
 
 @interface BrowserViewController ()<AppRatingPromptDelegate,
@@ -1102,11 +1112,16 @@ class BrowserBookmarkModelBridge : public bookmarks::BookmarkModelObserver {
 - (BOOL)canShowFindBar {
   // Make sure web controller can handle find in page.
   Tab* tab = [_model currentTab];
-  if (![tab.findInPageController canFindInPage])
+  FindTabHelper* findHelper = GetFindTabHelper(tab);
+  if (!findHelper)
+    return NO;
+
+  FindInPageController* controller = findHelper->GetController();
+  if (![controller canFindInPage])
     return NO;
 
   // Don't show twice.
-  if (tab.findInPageController.findInPageModel.enabled)
+  if (controller.findInPageModel.enabled)
     return NO;
 
   return YES;
@@ -1473,7 +1488,14 @@ class BrowserBookmarkModelBridge : public bookmarks::BookmarkModelObserver {
   DCHECK(tab && ([_model indexOfTab:tab] != NSNotFound));
   // Hide find bar when navigating to a new page.
   [self hideFindBarWithAnimation:NO];
-  tab.findInPageController.findInPageModel.enabled = NO;
+
+  FindTabHelper* findHelper = GetFindTabHelper(tab);
+  if (findHelper) {
+    FindInPageController* controller =
+        findHelper->GetController();
+    controller.findInPageModel.enabled = NO;
+  }
+
   if (tab == [_model currentTab]) {
     // TODO(pinkerton): Fill in here about hiding the forward button on
     // navigation.
@@ -1936,10 +1958,15 @@ class BrowserBookmarkModelBridge : public bookmarks::BookmarkModelObserver {
     [[_toolbarController toolsPopupController]
         setIsTabLoading:_toolbarModelIOS->IsLoading()];
 
-  if (tab.findInPageController.findInPageModel.enabled)
-    [self showFindBarWithAnimation:NO
-                        selectText:YES
-                       shouldFocus:[_findBarController isFocused]];
+  FindTabHelper* findHelper = GetFindTabHelper(tab);
+  if (findHelper) {
+    FindInPageController* controller =
+        findHelper->GetController();
+    if (controller.findInPageModel.enabled)
+      [self showFindBarWithAnimation:NO
+            selectText:YES
+            shouldFocus:[_findBarController isFocused]];
+  }
 
   // Hide the toolbar if displaying phone NTP.
   if (!IsIPadIdiom()) {
@@ -3959,24 +3986,28 @@ class BrowserBookmarkModelBridge : public bookmarks::BookmarkModelObserver {
     case IDC_FIND:
       [self initFindBarForTab];
       break;
-    case IDC_FIND_NEXT:
+    case IDC_FIND_NEXT: {
+      FindInPageController* findInPageController =
+          FindTabHelper::FromWebState([_model currentTab].webState)

[Eugene But (OOO till 7-30), 2017/01/31 19:03:48]

Should you use your helper function here and in other places?

[rohitrao (ping after 24h), 2017/02/08 16:14:59]

Changed for now, but I'm going to revisit.  I think in some of these places it's
safe to assume that |tab| is not nil.

+              ->GetController();
       // TODO(crbug.com/603524): Reshow find bar if necessary.
-      [[_model currentTab].findInPageController
-          findNextStringInPageWithCompletionHandler:^{
-            FindInPageModel* model =
-                [_model currentTab].findInPageController.findInPageModel;
-            [_findBarController updateResultsCount:model];
-          }];
+      [findInPageController findNextStringInPageWithCompletionHandler:^{
+        FindInPageModel* model = findInPageController.findInPageModel;
+        [_findBarController updateResultsCount:model];
+      }];
       break;
-    case IDC_FIND_PREVIOUS:
+    }
+    case IDC_FIND_PREVIOUS: {
+      FindInPageController* findInPageController =
+          FindTabHelper::FromWebState([_model currentTab].webState)
+              ->GetController();
       // TODO(crbug.com/603524): Reshow find bar if necessary.
-      [[_model currentTab].findInPageController
-          findPreviousStringInPageWithCompletionHandler:^{
-            FindInPageModel* model =
-                [_model currentTab].findInPageController.findInPageModel;
-            [_findBarController updateResultsCount:model];
-          }];
+      [findInPageController findPreviousStringInPageWithCompletionHandler:^{
+        FindInPageModel* model = findInPageController.findInPageModel;
+        [_findBarController updateResultsCount:model];
+      }];
       break;
+    }
     case IDC_FIND_CLOSE:
       [self closeFindInPage];
       break;
@@ -4215,15 +4246,22 @@ class BrowserBookmarkModelBridge : public bookmarks::BookmarkModelObserver {
   [self hidePageInfoPopupForView:nil];
   if (_voiceSearchController)
     _voiceSearchController->DismissMicPermissionsHelp();
-  [[_model currentTab] dismissModals];
-  [[_model currentTab].findInPageController
-      disableFindInPageWithCompletionHandler:^{
+
+  Tab* currentTab = [_model currentTab];
+  [currentTab dismissModals];
+
+  FindTabHelper* findHelper = GetFindTabHelper(currentTab);
+  if (findHelper) {
+    FindInPageController* findInPageController =
+        findHelper
+        ->GetController();
+    [findInPageController disableFindInPageWithCompletionHandler:^{
         [self updateFindBar:NO shouldFocus:NO];
       }];
-  [_contextualSearchController movePanelOffscreen];
+  }
 
+  [_contextualSearchController movePanelOffscreen];
   [_paymentRequestManager cancelRequest];
-
   [_printController dismissAnimated:YES];
   _printController.reset();
   if (_noTabsController.get())
@@ -4323,40 +4361,46 @@ class BrowserBookmarkModelBridge : public bookmarks::BookmarkModelObserver {
         [[FindBarControllerIOS alloc] initWithIncognito:_isOffTheRecord]);
 
   Tab* tab = [_model currentTab];
-  DCHECK(!tab.findInPageController.findInPageModel.enabled);
-  tab.findInPageController.findInPageModel.enabled = YES;
+  FindInPageController* controller =
+      FindTabHelper::FromWebState(tab.webState)->GetController();
+  DCHECK(!controller.findInPageModel.enabled);
+  controller.findInPageModel.enabled = YES;
   [self showFindBarWithAnimation:YES selectText:YES shouldFocus:YES];
 }
 
 - (void)searchFindInPage {
   FindInPageController* findInPageController =
-      [[_model currentTab] findInPageController];
+      FindTabHelper::FromWebState([_model currentTab].webState)
+          ->GetController();
   base::WeakNSObject<BrowserViewController> weakSelf(self);
-  [findInPageController
-       findStringInPage:[_findBarController searchTerm]
-      completionHandler:^{
-        FindInPageModel* model =
-            [_model currentTab].findInPageController.findInPageModel;
-        [_findBarController updateResultsCount:model];
-      }];
+  [findInPageController findStringInPage:[_findBarController searchTerm]
+                       completionHandler:^{
+                         FindInPageModel* model =
+                             findInPageController.findInPageModel;
+                         [_findBarController updateResultsCount:model];
+                       }];
   if (!_isOffTheRecord)
     [findInPageController saveSearchTerm];
 }
 
 - (void)closeFindInPage {
   base::WeakNSObject<BrowserViewController> weakSelf(self);
-  [[_model currentTab].findInPageController
-      disableFindInPageWithCompletionHandler:^{
-        [weakSelf updateFindBar:NO shouldFocus:NO];
-      }];
+  FindInPageController* findInPageController =
+      FindTabHelper::FromWebState([_model currentTab].webState)
+          ->GetController();
+  [findInPageController disableFindInPageWithCompletionHandler:^{
+    [weakSelf updateFindBar:NO shouldFocus:NO];
+  }];
 }
 
 - (void)updateFindBar:(BOOL)initialUpdate shouldFocus:(BOOL)shouldFocus {
-  FindInPageModel* model =
-      [_model currentTab].findInPageController.findInPageModel;
+  FindInPageController* findInPageController =
+      FindTabHelper::FromWebState([_model currentTab].webState)
+          ->GetController();
+  FindInPageModel* model = findInPageController.findInPageModel;
   if (model.enabled) {
     if (initialUpdate && !_isOffTheRecord) {
-      [[_model currentTab].findInPageController restoreSearchTerm];
+      [findInPageController restoreSearchTerm];
     }
 
     [self setFramesForHeaders:[self headerViews]