Consistently check if a block can handle pagination strut propagation.

https://codereview.chromium.org/1360753002 got it right for inline child
layout, but did nothing for block child layout.

BUG=329421
R=jchaffraix@chromium.org,leviw@chromium.org

Review URL: https://codereview.chromium.org/1387553002

Cr-Commit-Position: refs/heads/master@{#352429}
LayoutUnit LayoutBlockFlow::adjustLogicalLeftOffsetForLine(LayoutUnit offsetFromFloats, bool applyTextIndent) const
{
    LayoutUnit left = offsetFromFloats;

    if (applyTextIndent && style()->isLeftToRightDirection())
        left += textIndentOffset();

    return left;
}

LayoutUnit LayoutBlockFlow::adjustLogicalLeftOffsetForLine(LayoutUnit offsetFromFloats, bool applyTextIndent) const
{
    LayoutUnit left = offsetFromFloats;

    if (applyTextIndent && style()->isLeftToRightDirection())
        left += textIndentOffset();

    return left;
}
