FontCachePurgePreventer is needed when computing MinPreferredWidth

third_party/WebKit/Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 3239 matching lines @@
         ->view()
         ->updateLifecycleToCompositingCleanPlusScrolling();
 
   Document* document = m_page->mainFrame()->isLocalFrame()
                            ? m_page->deprecatedLocalMainFrame()->document()
                            : nullptr;
   if (!document || document->layoutViewItem().isNull() ||
       !document->documentElement() || !document->documentElement()->layoutBox())
     return WebSize();
 
+  // Needed for computing minPreferredWidth.
+  FontCachePurgePreventer fontCachePurgePreventer;
   int widthScaled = document->layoutViewItem()
                         .minPreferredLogicalWidth()
                         .round();  // Already accounts for zoom.
   int heightScaled =
       document->documentElement()->layoutBox()->scrollHeight().round();
   return IntSize(widthScaled, heightScaled);
 }
 
 float WebViewImpl::defaultMinimumPageScaleFactor() const {
   return pageScaleConstraintsSet().defaultConstraints().minimumScale;
@@ skipping 904 matching lines @@
   if (focusedFrame->localFrameRoot() != mainFrameImpl()->frame())
     return nullptr;
   return focusedFrame;
 }
 
 LocalFrame* WebViewImpl::focusedLocalFrameAvailableForIme() const {
   return m_imeAcceptEvents ? focusedLocalFrameInWidget() : nullptr;
 }
 
 }  // namespace blink