Make Range::TextQuads() to use ComputeTextBounds() template function.

This is CL#3 to achieve the template behaviour for Range::textQuads
and Range::textRects.
CL#2(https://codereview.chromium.org/2839633002/) ComputeTextBounds(),
template and was used by Range::computeTextRects() only.
This CL set will make Range::textQuads() to use ComputeTextBounds() template.

BUG=691198

Review-Url: https://codereview.chromium.org/2854043002
Cr-Commit-Position: refs/heads/master@{#470345}
1 file changed