Update style and layout tree explicitly for svg images.

Trying to remove the forced UpdateStyleAndLayoutTree on finished parsing
caused svg image regressions becaused it relied on it. Instead make that
dependency explicit for svg images.

Bug: 742413
Change-Id: I74b5f238651348dbb0dff4fa3002525a526e5275
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1624565
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Reviewed-by: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#662160}

third_party/blink/renderer/core/svg/graphics/svg_image.cc

@@ -810,6 +810,10 @@ Image::SizeAvailability SVGImage::DataChanged(bool all_data_received) {
 
   frame->ForceSynchronousDocumentInstall("image/svg+xml", Data());
 
+  // Intrinsic sizing relies on computed style (e.g. font-size and
+  // writing-mode).
+  frame->GetDocument()->UpdateStyleAndLayoutTree();
+
   // Set the concrete object size before a container size is available.
   intrinsic_size_ = RoundedIntSize(ConcreteObjectSize(FloatSize(
       LayoutReplaced::kDefaultWidth, LayoutReplaced::kDefaultHeight)));