Blink style: Reduce the size of computed_style.h

computed_style.h is used in 1,300+ compilation units, and this CL
reduces its pre-processed size by 1.09MB.

* Avoid including image_resource_content.h
 image_resource_content.h is large due to dependency to mojom files.
 Stop inlining ShapeValue::IsImageValid().

* Avoid including style_svg_resource.h
  style_svg_resource.h and svg_resource.h are large due to
  dependency to mojom files.
 - Stop inlining many functions using StyleSVGResource and
   SVGResource.
 - Move ReferenceClipPathOperation and ShapeClipPathOperation
   to their own files.
 - Fix make_css_property_subclasses.py for generated
   core/css/properties/longhands/marker_*.h, which depend on
   StyleSVGResource.

Bug: 242216
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I907a7772283b282a410fb47f457c447d5417f650
Reviewed-on: https://chromium-review.googlesource.com/1128794
Commit-Queue: Kent Tamura <tkent@chromium.org>
Reviewed-by: Anders Ruud <andruud@chromium.org>
Cr-Commit-Position: refs/heads/master@{#573473}
25 files changed