Revert "Add a build target and a proper export header for shared library builds."

This reverts commit 00334675c18a0203f313cceb670c970a77280f49.

Reason for revert: Breaking the deps roller - https://chromium-review.googlesource.com/c/609307

Original change's description:
> Add a build target and a proper export header for shared library builds.
> 
> This CL adds support for Chromium's component build feature to pdfium.
> 
> The export header stub in fpdfview.h is expanded to match Chromium's
> export mechanisms and patterns (fixes pdfium:825).
> 
> A component/shared library build can be triggered by adding
> 
> is_component_build = true
> 
> as a gn argument. Please note that setting this will also affect some
> of pdfiums dependencies like v8, which will be build as components
> too.
> 
> Additionally, this CL provides a "pdf_source_set" template which
> dynamically enables the use of "source_set" when building a complete
> static library or a shared library to reduce build time.
> 
> When testing this it is recommended to only build the pdfium target as
> most of pdfiums test rely on non-public functions which aren't exported
> by the shared library.
> 
> Bug: pdfium:825,pdfium:826
> Change-Id: Icedc538ec535e11d1e53c4d5fabc8c064b275752
> Reviewed-on: https://pdfium-review.googlesource.com/8970
> Reviewed-by: dsinclair <dsinclair@chromium.org>
> Commit-Queue: dsinclair <dsinclair@chromium.org>

TBR=thestig@chromium.org,tsepez@chromium.org,brucedawson@chromium.org,dsinclair@google.com,dsinclair@chromium.org,licorn@gmail.com

Change-Id: Ib02af2298932481293f50d362ae87bfedf284821
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: pdfium:825, pdfium:826
Reviewed-on: https://pdfium-review.googlesource.com/10550
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>

0 files changed, 0 insertions, 0 deletions