Unify and Improve the Sign-In and Sync Confirmation Screens on Clank.

chrome/android/java/src/org/chromium/chrome/browser/firstrun/ImageCarousel.java

Index: chrome/android/java/src/org/chromium/chrome/browser/firstrun/ImageCarousel.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/firstrun/ImageCarousel.java b/chrome/android/java/src/org/chromium/chrome/browser/firstrun/ImageCarousel.java
index df5a61f7a456b7fccc045f36258de5f03fb01d21..4fb92ef555e1b9fb6b4f26ba6e96a7f6b70673ce 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/firstrun/ImageCarousel.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/firstrun/ImageCarousel.java
@@ -220,25 +220,38 @@ public class ImageCarousel extends FrameLayout implements GestureDetector.OnGest
         updateImageViews();
     }
 
+    ImageView mCheckmark;

[newt (away), 2016/02/03 17:57:29]

Make this private and put it with the other member variables

[PEConn, 2016/02/04 19:26:10]

Done.

     /**
-     * Sets the ImageCarousel to signed in mode that disables scrolling, animates away the
-     * background images, and displays a checkmark next to the account image that was chosen.
+     * Sets whether the ImageCarousel is in signed in mode. This mode disables scrolling, animates
+     * away the background images, and displays a checkmark next to the chosen account image.
+     * @param isSignedIn Whether the ImageCarousel should in signed in mode or not.
      */
-    public void setSignedInMode() {
-        mScrollingDisabled = true;
-        mAccountSelected = true;
+    public void setSignedInMode(boolean isSignedIn) {
+        mScrollingDisabled = isSignedIn;
+        mAccountSelected = isSignedIn;
         setPosition(getCenterPosition());
 
-        ImageView checkmark = new ImageView(getContext());
-        checkmark.setImageResource(R.drawable.verify_checkmark);
-        setLayoutParamsForCheckmark(checkmark);
-        addView(checkmark);
+        if (mCheckmark == null) {
+            // If the checkmark hasn't been created and we don't want to show it, exit early.
+            if (!isSignedIn) {
+                return;

[newt (away), 2016/02/03 17:57:29]

Early returns hidden in the middle of a method can be dangerous; it's easy for a
later developer to miss the early return and introduce bugs.

Here's another way to do this:
 - Add a member variable mIsSignedInMode
 - If isSignedIn == mIsSignInMode, then early return right at the beginning of
this method.

[PEConn, 2016/02/04 19:26:10]

Done.

+            }
+
+            mCheckmark = new ImageView(getContext());
+            mCheckmark.setImageResource(R.drawable.verify_checkmark);
+            setLayoutParamsForCheckmark(mCheckmark);
+            addView(mCheckmark);
+        }
 
         if (mFadeInOutAnimator != null) mFadeInOutAnimator.cancel();
         AnimatorSet animatorSet = new AnimatorSet();
-        animatorSet.playTogether(
-                ObjectAnimator.ofFloat(this, BACKGROUND_IMAGE_ALPHA, 0),
-                ObjectAnimator.ofFloat(checkmark, View.ALPHA, 0.0f, 1.0f));
+        if (isSignedIn) {
+            animatorSet.playTogether(ObjectAnimator.ofFloat(this, BACKGROUND_IMAGE_ALPHA, 0),
+                    ObjectAnimator.ofFloat(mCheckmark, View.ALPHA, 0.0f, 1.0f));
+        } else {
+            animatorSet.playTogether(ObjectAnimator.ofFloat(this, BACKGROUND_IMAGE_ALPHA, 1),
+                    ObjectAnimator.ofFloat(mCheckmark, View.ALPHA, 1.0f, 0.0f));
+        }
         mFadeInOutAnimator = animatorSet;
         mFadeInOutAnimator.setDuration(ACCOUNT_SIGNED_IN_ANIMATION_DURATION_MS);
         mFadeInOutAnimator.start();