Fix initial kerning when there is a horzscale set
Fix initial kerning when there is a horzscale set

Reasoning: the pTextAdvanceX in CPDF_TextObject::CalcPositionData is
being multiplied by horz_scale in CPDF_TextObject::CalcPositionData.
Then, m_pCurStates->m_TextX is updated by this amount. So multiply by
the scale also when updating with initial and final kerning and when
nsegs = 0.

BUG=528103

Review-Url: https://codereview.chromium.org/2542743002

DrAlexx/pdfium,DrAlexx/pdfium,DrAlexx/pdfium,DrAlexx/pdfium