title: Android SeekBar can't be full width even set padding 0 in AppCompat 23.1.0
body: <p>when I update android support lib from 23.0.1 to 23.1.0, I find the SeekBar is not full width any more.</p>
  
  <p>this is the test XML file:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout
      xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:divider="@drawable/space_divider"
      android:orientation="vertical"
      android:padding="8dp"
      android:showDividers="middle"&gt;
  
      &lt;View
          android:layout_width="match_parent"
          android:layout_height="20dp"
          android:background="@android:color/black"/&gt;
  
      &lt;!-- default SeekBar --&gt;
      &lt;SeekBar
          android:layout_width="match_parent"
          android:layout_height="10dp"
          android:progress="50"
          android:progressTint="@android:color/holo_red_dark"/&gt;
  
      &lt;!-- padding=0 --&gt;
      &lt;SeekBar
          android:layout_width="match_parent"
          android:layout_height="10dp"
          android:padding="0dp"
          android:progress="50"
          android:progressTint="@android:color/holo_red_dark"/&gt;
  
      &lt;!-- padding=40 --&gt;
      &lt;SeekBar
          android:layout_width="match_parent"
          android:layout_height="10dp"
          android:padding="40dp"
          android:progress="50"
          android:progressTint="@android:color/holo_red_dark"/&gt;
  
      &lt;android.support.v7.widget.AppCompatSeekBar
          android:layout_width="match_parent"
          android:layout_height="10dp"
          android:padding="0dp"
          android:progress="50"/&gt;
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>It works well under support lib 23.0.1, like following screenshot. SeekBar has default padding, when I set padding=0 manual, it can be full width. and AppCompatSeekBar is not exist yet.</p>
  
  <p><a href="https://i.stack.imgur.com/J3qj3.png" rel="noreferrer"><img src="https://i.stack.imgur.com/J3qj3.png" alt="enter image description here"></a></p>
  
  <p>but under support lib 23.1.0, whether I set how much of padding, SeekBar and AppCompatSeekBar has no any change, like following screenshot.</p>
  
  <p><a href="https://i.stack.imgur.com/ORaai.png" rel="noreferrer"><img src="https://i.stack.imgur.com/ORaai.png" alt="enter image description here"></a></p>
  
  <p>so, is this the bug of support lib, any body meet this problem and how to resolve it?</p>
  
  <p>thank you~!</p>
  
  <p>update:<br>
  It totally confused me, I just have another test, I create a new project, whether I use AppCompat 23.0.1 or 23.1.0, SeekBar neither can be full width after set padding=0, (the compileSdkVersion is 23, buildToolsVersion is "23.0.1", targetSdkVersion is 23). anyway, I want to know how to make SeekBar full width when set padding=0 not work.</p>
  
  <p>the build.gradle:</p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
      compileSdkVersion 23
      buildToolsVersion "23.0.1"
  
      defaultConfig {
          applicationId "com.test.seekbar"
          minSdkVersion 14
          targetSdkVersion 23
          versionCode 1
          versionName "1.0"
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  }
  
  dependencies {
      compile fileTree(dir: 'libs', include: ['*.jar'])
      testCompile 'junit:junit:4.12'
      compile 'com.android.support:appcompat-v7:23.0.1'
  }
  </code></pre>