[Passwords] Touch To Fill Fixes

This change introduces a couple of small fixes to the Touch To Fill
feature. In particular, it breaks a circular dependency between the
constructors of the TouchToFillController and the
ManualFillingController and exposes the Touch to Fill feature flag to
Android.

Bug: 957532
Change-Id: Id1c9f227139d7b5273d1db6b0ca13a5004addf52
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1649513
Commit-Queue: Vasilii Sukhanov <vasilii@chromium.org>
Auto-Submit: Jan Wilken Dörrie <jdoerrie@chromium.org>
Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#667173}

chrome/browser/android/chrome_feature_list.cc

@@ -210,6 +210,7 @@ const base::Feature* kFeaturesExposedToJava[] = {
     &omnibox::kUIExperimentShowSuggestionFavicons,
     &password_manager::features::kGooglePasswordManager,
     &password_manager::features::kPasswordsKeyboardAccessory,
+    &password_manager::features::kTouchToFillAndroid,
     &safe_browsing::kCaptureSafetyNetId,
     &signin::kMiceFeature,
     &switches::kSyncSendTabToSelf,

chrome/browser/password_manager/touch_to_fill_controller.cc

@@ -63,7 +63,8 @@ void TouchToFillController::Show(
                         /*is_selectable=*/false);
   }
 
-  mf_controller_->ShowTouchToFillSheet(std::move(builder).Build());
+  GetManualFillingController()->ShowTouchToFillSheet(
+      std::move(builder).Build());
 }
 
 void TouchToFillController::OnFillingTriggered(
@@ -79,9 +80,7 @@ void TouchToFillController::OnOptionSelected(
 }
 
 TouchToFillController::TouchToFillController(WebContents* web_contents)
-    : mf_controller_(ManualFillingController::GetOrCreate(web_contents)) {
-  DCHECK(mf_controller_);
-}
+    : web_contents_(web_contents) {}
 
 TouchToFillController::TouchToFillController(
     base::WeakPtr<ManualFillingController> mf_controller)
@@ -89,4 +88,11 @@ TouchToFillController::TouchToFillController(
   DCHECK(mf_controller_);
 }
 
+ManualFillingController* TouchToFillController::GetManualFillingController() {
+  if (!mf_controller_)
+    mf_controller_ = ManualFillingController::GetOrCreate(web_contents_);
+  DCHECK(mf_controller_);
+  return mf_controller_.get();
+}
+
 WEB_CONTENTS_USER_DATA_KEY_IMPL(TouchToFillController)

chrome/browser/password_manager/touch_to_fill_controller.h

@@ -61,6 +61,15 @@ class TouchToFillController
   explicit TouchToFillController(
       base::WeakPtr<ManualFillingController> mf_controller);
 
+  // Lazy-initializes and returns the ManualFillingController for the current
+  // |web_contents_|. The lazy initialization is required to break a circular
+  // dependency between the constructors of the TouchToFillController and
+  // ManualFillingController.
+  ManualFillingController* GetManualFillingController();
+
+  // The tab for which this class is scoped.
+  content::WebContents* web_contents_ = nullptr;
+
   // The manual filling controller object to forward client requests to.
   base::WeakPtr<ManualFillingController> mf_controller_;