Revert of PDF: remove last use of SkPDFImage

Revert of PDF: remove last use of SkPDFImage (patchset #5 id:120001 of https://codereview.chromium.org/950633003/)

Reason for revert:
static void draw(SkCanvas* canvas,
                 const SkPaint& p,
                 const SkBitmap& src,
                 SkColorType colorType,
                 const char text[]) {
    SkASSERT(src.colorType() == colorType);
    canvas->drawBitmap(src, 0.0f, 0.0f);
    canvas->drawText(text, strlen(text), 0.0f, 12.0f, p);
}

This assert is firing, at least on macs, where all images get decoded into 32bit at the moment.

Original issue's description:
> PDF: remove last use of SkPDFImage
> 
> Add a GM.
> 
> BUG=skia:255
> 
> Committed: https://skia.googlesource.com/skia/+/86ad8d643624a55b02e529100bbe4e2940115fa1

TBR=mtklein@google.com,halcanary@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:255
Committed: https://skia.googlesource.com/skia/+/1b600d3446b3d236bfa06cf116ec41960bea6ac8

[reed1, 2015-03-20 17:02:59]

Created Revert of PDF: remove last use of SkPDFImage

[commit-bot: I haz the power, 2015-03-20 17:03:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1024113002/1

[commit-bot: I haz the power, 2015-03-20 17:03:43]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/1b600d3446b3d236bfa06cf116ec41960bea6ac8