Split DarkModeImageClassifier for Bitmap and SVG images.

The classifier for SVG images is going to have to work with
layout objects. So the code for the SVG classifier cannot
reside in the current DarkModeImageClassifier in platform
as the code in platform cannot depend on core.

A separate class is implemented in core for classification
of SVG images in dark mode. The current DarkModeImageClassifier
is renamed to a more appropriate DarkModeBitmapImageClassifier.

The SVG classifier itself is a work in progress and will be
submitted in a follow-up CL.

Bug: 949943
Change-Id: I135a357c333655c11e197599466c314d2f20facf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1564276
Commit-Queue: Varun Chowdhary Paturi <v.paturi@samsung.com>
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652495}
12 files changed