Invalidate the text autosizer on meta viewport settings changes

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

Index: third_party/WebKit/Source/core/page/Page.cpp
diff --git a/third_party/WebKit/Source/core/page/Page.cpp b/third_party/WebKit/Source/core/page/Page.cpp
index 01e625f804c21cfbb0c1f2d0613081a300cf7636..e9ff729a99b9b02ac257460a85db1a309fe42e21 100644
--- a/third_party/WebKit/Source/core/page/Page.cpp
+++ b/third_party/WebKit/Source/core/page/Page.cpp
@@ -340,8 +340,12 @@ void Page::settingsChanged(SettingsDelegate::ChangeType changeType)
         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()) {