Revert "[pdf] Enable the Skia Path code in Chrome"

This reverts commit 1545ba9.

Reason for revert: Ran into some font issues, and a bunch of clusterfuzz bugs.


Original change's description:
> [pdf] Enable the Skia Path code in Chrome
> 
> This Cl enables the PDFium code to use Skia to render paths instead of
> Anti-Grain Geometry.
> 
> This is a reland of the CL reverted in:
> https://codereview.chromium.org/2778843003/
> 
> Bug: pdfium:11
> Change-Id: Id7727022d8e68c626d8393df76652c036239b342
> Reviewed-on: https://chromium-review.googlesource.com/543296
> Reviewed-by: Lei Zhang <thestig@chromium.org>
> Reviewed-by: Andrew Grieve <agrieve@chromium.org>
> Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#481561}

TBR=thestig@chromium.org,dsinclair@chromium.org,brettw@chromium.org,caryclark@chromium.org,agrieve@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: pdfium:11
Change-Id: I2f28b4b453aba6c83647ba2ffd12f672181f0163
Reviewed-on: https://chromium-review.googlesource.com/548098
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
Cr-Commit-Position: refs/heads/master@{#482271}

build_overrides/pdfium.gni

@@ -15,8 +15,8 @@ pdf_bundle_freetype_override = false
 # Disable use of Skia backend.
 pdf_use_skia_override = false
 
-# Enable use of Skia backend, paths only.
-pdf_use_skia_paths_override = true
+# Disable use of Skia backend, paths only (experimental)
+pdf_use_skia_paths_override = false
 
 # Enable experimental win32 GDI APIs.
 pdf_use_win32_gdi_override = true