Invalidate the text autosizer on meta viewport settings changes

third_party/WebKit/Source/core/page/Page.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All Rights Reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 322 matching lines @@
     return m_isCursorVisible && settings().deviceSupportsMouse();
 }
 
 void Page::settingsChanged(SettingsDelegate::ChangeType changeType)
 {
     switch (changeType) {
     case SettingsDelegate::StyleChange:
         setNeedsRecalcStyleInAllFrames();
         break;
     case SettingsDelegate::ViewportDescriptionChange:
-        if (mainFrame() && mainFrame()->isLocalFrame())
+        if (mainFrame() && mainFrame()->isLocalFrame()) {
             deprecatedLocalMainFrame()->document()->updateViewportDescription();
+            // The text autosizer has dependencies on the viewport.
+            if (TextAutosizer* textAutosizer = deprecatedLocalMainFrame()->document()->textAutosizer())
+                textAutosizer->updatePageInfoInAllFrames();

[rune, 2016/09/15 08:43:18]

Wouldn't this also be an issue when you set the viewport meta late. That is,
after you have layed out once?

If so, I think this should be handled where the viewport is updated.

[skobes, 2016/09/16 01:19:57]

It looks like we already call updatePageInfoInAllFrames from
WebViewImpl::updatePageDefinedViewportConstraints, which gets called when the
viewport meta changes.

But in that case I am not sure why we also need it here?

[pdr., 2016/09/17 05:14:53]

This should only be called for settings changes like in the test, but not for
actual viewport changes from users.

We do update the text autosizer in updatePageDefinedViewportConstraints but
there's an early out before then if the viewport setting is not enabled. We
could update the autosizer when the viewport setting is not enabled too, but
that seems heavyweight for a bug that only occurs on settings changes.

+        }
         break;
     case SettingsDelegate::DNSPrefetchingChange:
         for (Frame* frame = mainFrame(); frame; frame = frame->tree().traverseNext()) {
             if (frame->isLocalFrame())
                 toLocalFrame(frame)->document()->initDNSPrefetch();
         }
         break;
     case SettingsDelegate::ImageLoadingChange:
         for (Frame* frame = mainFrame(); frame; frame = frame->tree().traverseNext()) {
             if (frame->isLocalFrame()) {
@@ skipping 167 matching lines @@
 {
 }
 
 Page::PageClients::~PageClients()
 {
 }
 
 template class CORE_TEMPLATE_EXPORT Supplement<Page>;
 
 } // namespace blink