Correctly handle negative margins in horizontal linear layouts.
Correctly handle negative margins in horizontal linear layouts.

When LinearLayout is measured in EXACTLY mode, we handle the negative margins
a bit differently. This is to support the use case of the current tab design.

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base