Update account and sync management UX

chrome/android/java/res/layout/sync_custom_passphrase.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright 2015 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. -->
 
 <ScrollView
     xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:chrome="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:overScrollMode="ifContentScrolls">
     <LinearLayout
         android:orientation="vertical"
         style="@style/AlertDialogContent">
-        <TextView
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:layout_marginBottom="25dp"
-            android:text="@string/sync_custom_passphrase"/>
         <org.chromium.chrome.browser.widget.AlertDialogEditText
             android:id="@+id/passphrase"
             android:hint="@string/sync_enter_custom_passphrase_hint"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:inputType="textPassword"
             android:singleLine="true"
             android:imeOptions="actionNext" />
         <org.chromium.chrome.browser.widget.AlertDialogEditText
             android:id="@+id/confirm_passphrase"
             android:hint="@string/sync_enter_custom_passphrase_hint_confirm"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:inputType="textPassword"
             android:singleLine="true"
             android:imeOptions="actionDone" />
+        <TextView
+            android:id="@+id/custom_passphrase_instructions"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginBottom="25dp"

[newt (away), 2016/02/16 23:05:01]

Still seems like a lot of extra padding/margin. Does this match the mocks?

[May, 2016/02/17 13:24:31]

It does visually. I don't have any vizd for actual numbers.

[newt (away), 2016/02/17 19:34:41]

Ok. Sometimes counting pixels in GIMP is the best option :)

+            android:layout_marginTop="25dp"
+            android:text="@string/sync_custom_passphrase"
+            chrome:helpContext="@string/help_context_clear_browsing_data" />

[newt (away), 2016/02/16 23:05:01]

Huh? chrome:helpContext is used for the LearnMorePreference. It doesn't apply to
TextViews.

[May, 2016/02/17 13:24:31]

Ugh, missed this before uploading. Removed.

     </LinearLayout>
 </ScrollView>