Set default SVG image font settings

Source/core/svg/graphics/SVGImage.cpp

 /*
  * Copyright (C) 2006 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 416 matching lines @@
         // This will become an issue when SVGImage will be able to load other
         // SVGImage objects, but we're safe now, because SVGImage can only be
         // loaded by a top-level document.
         OwnPtrWillBeRawPtr<Page> page;
         {
             TRACE_EVENT0("blink", "SVGImage::dataChanged::createPage");
             page = adoptPtrWillBeNoop(new Page(pageClients));
             page->settings().setScriptEnabled(false);
             page->settings().setPluginsEnabled(false);
             page->settings().setAcceleratedCompositingEnabled(false);
+
+            // Because this page is detached, it can't get default font settings
+            // from the embedder. Copy over font settings so we have sensible
+            // defaults. These settings are fixed and will not update if changed.
+            if (!Page::ordinaryPages().isEmpty()) {

[Erik Dahlström, 2015/05/17 20:20:15]

Under what circumstances can ordinaryPages be empty?

[pdr., 2015/05/19 02:02:29]

I don't think it is possible to have ordinaryPages be empty when we hit this
code because some ordinary page needs to trigger the svg image load. I've added
an assert here to enforce that.

+                Settings& defaultSettings = (*Page::ordinaryPages().begin())->settings();

[Erik Dahlström, 2015/05/17 20:20:15]

This means svg images can get a different set of defaults if the first page gets
closed, right? If so, then that's not completely ideal, but it's still way
better than the current situation.

[pdr., 2015/05/19 02:02:29]

The defaults for these specific settings shouldn't change on a per-page basis so
I think we're good in that case. This patch doesn't support dynamic changes of
these values though.

+                page->settings().genericFontFamilySettings() = defaultSettings.genericFontFamilySettings();
+                page->settings().setMinimumFontSize(defaultSettings.minimumFontSize());
+                page->settings().setMinimumLogicalFontSize(defaultSettings.minimumLogicalFontSize());
+                page->settings().setDefaultFontSize(defaultSettings.defaultFontSize());
+                page->settings().setDefaultFixedFontSize(defaultSettings.defaultFixedFontSize());
+            }
         }
 
         RefPtrWillBeRawPtr<LocalFrame> frame = nullptr;
         {
             TRACE_EVENT0("blink", "SVGImage::dataChanged::createFrame");
             frame = LocalFrame::create(dummyFrameLoaderClient, &page->frameHost(), 0);
             frame->setView(FrameView::create(frame.get()));
             frame->init();
         }
 
@@ skipping 16 matching lines @@
 
     return m_page;
 }
 
 String SVGImage::filenameExtension() const
 {
     return "svg";
 }
 
 }