[Skia] Include SVG paint device sources

This is used by [1] to convert vector icons to SVGs, which are required
by Linux platform APIs for status icons.

[1] https://chromium-review.googlesource.com/c/chromium/src/+/6139403

Change-Id: I836ef0d517fdedd0db0d2fb2e8023426045dc69a
Bug: None
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6136155
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1401832}

skia/BUILD.gn

@@ -396,13 +396,17 @@ component("skia") {
     sources += skia_xml_sources
     sources += skia_codec_xmp
     sources += skia_codec_jpeg_xmp
+    sources += [
+      "//third_party/skia/src/svg/SkSVGCanvas.cpp",
+      "//third_party/skia/src/svg/SkSVGDevice.cpp",
+    ]
     deps += [ "//third_party/expat" ]
     defines += [ "SK_CODEC_DECODES_JPEG_GAINMAPS" ]
+  } else {
+    # Remove unused util sources.
+    sources -= [ "//third_party/skia/src/utils/SkParsePath.cpp" ]
   }
 
-  # Remove unused util sources.
-  sources -= [ "//third_party/skia/src/utils/SkParsePath.cpp" ]
-
   if (is_win) {
     libs = [ "fontsub.lib" ]
   }