Blink doesn't honor percent heights on children of "align-self:stretch" flex items in a fixed-height

Source/core/rendering/RenderBox.cpp

Index: Source/core/rendering/RenderBox.cpp
diff --git a/Source/core/rendering/RenderBox.cpp b/Source/core/rendering/RenderBox.cpp
index 84b19d2eb371becd6decf590071582e834a54f76..a6952395c79a98bdf6dd11f132a2f8298f0824c2 100644
--- a/Source/core/rendering/RenderBox.cpp
+++ b/Source/core/rendering/RenderBox.cpp
@@ -2676,6 +2676,8 @@ LayoutUnit RenderBox::computePercentageLogicalHeight(const Length& height) const
         availableHeight = containingBlockChild->containingBlockLogicalWidthForContent();
     else if (hasOverrideContainingBlockLogicalHeight())
         availableHeight = overrideContainingBlockContentLogicalHeight();
+    else if (cb->hasOverrideContainingBlockLogicalHeight())

[cbiesinger, 2014/06/24 03:01:28]

So, we're now giving overrideContainingBlockLogicalHeight a new meaning. In
fact, it now has *two* incompatible meanings. That doesn't seem right? At the
very least, it seems confusing.

Cunningly, this will actually not break percentage sizing the flex item  itself
due to the child->style()->logicalHeight().isAuto() check and the ordering of
applying min/max, though perhaps that could cause problems with later relayouts.

But does this work correctly in all cases with grid?

How about making this much simpler: change this code to

  else if (cb->isFlexItemIncludingDeprecated())
      availableHeight = cb->overrideLogicalContentHeight();

(actually, we should probably add an isFlexItem() function that doesn't include
deprecated)

Then, you shouldn't even have to change RenderFlexibleBox.

[harpreet.sk, 2014/06/24 07:56:59]

We simply cannot change the code as 

else if (cb->isFlexItemIncludingDeprecated()) 
    availableHeight = cb->overrideLogicalContentHeight();

It will cause the browser to crash for our test cases. It is because it enters
the given api first without cb->overrideLogicalContentHeight being set. So with
this condtion becoming true will call overrideLogicalContentHeight which does
not exist and hence it will get crash.

 Currently the code

 else if (cb->hasOverrideLogicalContentHeight()) 
    availableHeight = cb->overrideLogicalContentHeight();

 is working fine for all the cases for grid but to avoid problems in future
relayouts we can add an additional check of isFlexItem(). In my new patch i have
added this check in order to avoid porblem.
Added the api isFlexItem() in RenderBox.h

+        availableHeight = cb->overrideContainingBlockContentLogicalHeight();
     else if (cb->isTableCell()) {
         if (!skippedAutoHeightContainingBlock) {
             // Table cells violate what the CSS spec says to do with heights. Basically we