SideBySide2: Clean up resizeCodeMirror() method

When this methods runs cmA cannot be null, the test is never true.

Compute the height only once and pass it to both instances, then
tell them to reflow any content. This is slightly easier to follow
and ensures the computed height is the same.

DiffTable does not need an onLoad() method. The widgets in question
default in their ui.xml to being visible. Passing false was asking
the method to make them visible, and they are already visible.

Change-Id: I9346791ce51b1727f3ab00f8c23a39cdc62ac940
2 files changed