Fix not autosizing ruby elements issue.

third_party/WebKit/Source/core/layout/LayoutText.cpp

Index: third_party/WebKit/Source/core/layout/LayoutText.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutText.cpp b/third_party/WebKit/Source/core/layout/LayoutText.cpp
index c79928f7f8e13723c215949a74acc73cea2907f8..951709fc72b5ba18a612a22a96590ca5d10254b5 100644
--- a/third_party/WebKit/Source/core/layout/LayoutText.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutText.cpp
@@ -1388,8 +1388,10 @@ void LayoutText::computePreferredLogicalWidths(
         fontData->getFontMetrics().floatDescent(), m_maxWidth);
   }
   // We shouldn't change our mind once we "know".
-  ASSERT(!m_knownToHaveNoOverflowAndNoFallbackFonts ||
-         (fallbackFonts.isEmpty() && glyphOverflow.isApproximatelyZero()));
+  if (!preferredLogicalWidthsDirty()) {

[pdr., 2017/02/10 04:10:46]

I think this dcheck should still work. Do you know why it needs the prefWidths
check?

[cathiechentx, 2017/02/10 05:17:47]

Hesitated to make this change too. The reason to fail this dcheck is:

1. After the first pass of layout, m_knownToHaveNoOverflowAndNoFallbackFonts is
true. Resized. Triggle layout.

2. Layout ruby. When autosize ruby, we changed ruby's inner layouttext's style
by setStyleInternal() in applyMultiplier(). setStyleInternal() won't change the
state of m_knownToHaveNoOverflowAndNoFallbackFonts. So
m_knownToHaveNoOverflowAndNoFallbackFonts remains true.

3. Layout rubyRun, rubyRun needs recalculate prefWidth. So it comes to here with
"m_knownToHaveNoOverflowAndNoFallbackFonts==true".

Maybe we could set m_knownToHaveNoOverflowAndNoFallbackFonts to false after we
changed the style of layouttext by setStyleInternal()?

[pdr., 2017/02/10 19:27:09]

Can you add a test for this? Just naively removing the conditional doesn't make
any tests hit this assert, but I see what you mean about how it can be hit.

If this dcheck is firing, is it because we have glyphOverflow when we didn't
before? I wonder if we need to force the entire ruby run to be recalculated
(maybe using setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation instead
of setNeedsLayoutAndFullPaintInvalidation)?

[cathiechentx, 2017/02/13 14:53:56]

fallbackFonts is not empty...

[cathiechentx, 2017/02/15 14:19:20]

Update:)

Actuall fallbackFonts is empty.

"If this dcheck is firing, is it because we have glyphOverflow when we didn't
before?"
Yes! The glyphOverflow of some font-family is different when font-size is
changed.

Analysis:
The below is the log of glyphOverflow printing before that 'DCHECK'.
They are the glyphOverflow of 'n' with 'font-family:Times New Roman;' and
font-size from 12px to 30px.
They are printed in SumSung Glaxy S4.
As we can see glyphOverflow is different when font-size is changed.
As a result of autosize the font-size could be changed when screen rotated.
It could change from glyphOverflow.isApproximatelyZero==true to
glyphOverflow.isApproximatelyZero==false.
So m_knownToHaveNoOverflowAndNoFallbackFonts could change from true to false
after screen rotated.
The test case 'ResizeAndGlyphOverflowChanged' could reproduce this issue.

Solution:
I think its reasonable to set 'm_knownToHaveNoOverflowAndNoFallbackFonts' false
of layoutText after this layoutText's computeSize is changed in
applyMultiplier() by setStyleInternal().
We do not know if there any change of glyphOverflow.

Log:
glyphOverflow=(0.000000, 0.259766, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.614746, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.000000, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.324707, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.000000, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.034668, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.389648, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.000000, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.099609, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.000000, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.000000, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.164551, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.000000, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.000000, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.229492, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.000000, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.000000, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.000000, 0.000000, 0.000000)
glyphOverflow=(0.000000, 0.000000, 0.000000, 0.000000)

+    DCHECK(!m_knownToHaveNoOverflowAndNoFallbackFonts ||
+           (fallbackFonts.isEmpty() && glyphOverflow.isApproximatelyZero()));
+  }
   m_knownToHaveNoOverflowAndNoFallbackFonts =
       fallbackFonts.isEmpty() && glyphOverflow.isApproximatelyZero();