title: TextInputLayout NullPointerException on setError
body: <p>I am using TextInputLayout as a container to hold country code and phone number. I have a custom style for this container.</p>
  
  <pre><code>&lt;android.support.design.widget.TextInputLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:id="@+id/signin_inputlayout_mobile"
          style="@style/UserAuthField"&gt;
  
          &lt;LinearLayout
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:orientation="horizontal"&gt;
  
              &lt;Spinner
                  android:layout_width="0dp"
                  android:layout_weight="22"
                  android:layout_height="wrap_content"
                  style="@style/region_spinner"
                  android:id="@+id/spinner"
                  android:prompt="@string/Auth_DialCode"&gt;
              &lt;/Spinner&gt;
  
              &lt;EditText
                  android:layout_width="0dp"
                  android:layout_weight="78"
                  style="@style/UserAuthField"
                  android:inputType="number"
                  android:id="@+id/usr_mobile_uname_login"
                  android:hint="@string/Auth_Phone"/&gt;
  
          &lt;/LinearLayout&gt;&lt;/android.support.design.widget.TextInputLayout&gt;
  </code></pre>
  
  <p>The following is the style:</p>
  
  <pre><code>&lt;style name="UserAuthField"&gt;
      &lt;item name="android:background"&gt;@drawable/etborder&lt;/item&gt;
      &lt;item name="android:layout_width"&gt;match_parent&lt;/item&gt;
      &lt;item name="android:layout_height"&gt;wrap_content&lt;/item&gt;
      &lt;item name="android:textColor"&gt;#333333&lt;/item&gt;
      &lt;item name="android:textColorHint"&gt;#757575&lt;/item&gt;
      &lt;item name="android:paddingBottom"&gt;4dp&lt;/item&gt;
      &lt;item name="android:paddingTop"&gt;8dp&lt;/item&gt;
  &lt;/style&gt;
  </code></pre>
  
  <p>Here's the layer-list:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;layer-list xmlns:android="http://schemas.android.com/apk/res/android"&gt;
  &lt;item android:bottom="1dp" android:left="-3dp" android:right="-3dp" android:top="-3dp"&gt;
      &lt;shape android:shape="rectangle"&gt;
          &lt;stroke android:width="1dp" android:color="#00FFFFFF"/&gt;
      &lt;/shape&gt;
  &lt;/item&gt;
  &lt;/layer-list&gt;
  </code></pre>
  
  <p>When I try to setError on this, I get the following error:</p>
  
  <pre><code>java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.setBackgroundTintList(android.content.res.ColorStateList)' on a null object reference
  </code></pre>
  
  <p>FYI, the same strategy worked earlier, but in this instance, something seems a miss. Can't figure out why?!</p>