最新的appCompat support library中，actionbar的自定义view不能占用全部的宽度

<style name="AppTheme" parent="Theme.AppCompat">
  <item name="toolbarStyle">@style/AppThemeToolbar</item>
  <item name="android:toolbarStyle">@style/AppThemeToolbar</item>
</style>

<style name="AppThemeToolbar" parent="Widget.AppCompat.Toolbar" >
  <item name="contentInsetStart">0dp</item>
  <item name="android:contentInsetStart">0dp</item>
</style>

reference: http://stackoverflow.com/questions/26433409/android-lollipop-appcompat-actionbar-custom-view-doesnt-take-up-whole-screen-w