[CSS Grid Layout] Avoid using StyleAdjuster to resolve 'auto' values.

LayoutTests/css3/flexbox/css-properties.html

Index: LayoutTests/css3/flexbox/css-properties.html
diff --git a/LayoutTests/css3/flexbox/css-properties.html b/LayoutTests/css3/flexbox/css-properties.html
index b43b9d5ea6aa3afcba0777a1e1116f9486200e51..a11448398f8d7434eb8c040fbc1a176d9ad409d6 100644
--- a/LayoutTests/css3/flexbox/css-properties.html
+++ b/LayoutTests/css3/flexbox/css-properties.html
@@ -53,8 +53,8 @@ shouldBeEqualToString('flexitem.style.order', '');
 
 
 shouldBeEqualToString('flexbox.style.justifyContent', '');
-// The initial value is 'flex-start'.
-shouldBeEqualToString('window.getComputedStyle(flexbox, null).justifyContent', 'flex-start');
+// The initial value is 'auto' which, will be resolve to 'stretch' for flexbox containers (behaving like 'flex-start' for the justify-content property).
+shouldBeEqualToString('window.getComputedStyle(flexbox, null).justifyContent', 'stretch');
 
 flexbox.style.justifyContent = 'foo';
 shouldBeEqualToString('flexbox.style.justifyContent', '');
@@ -77,7 +77,7 @@ shouldBeEqualToString('window.getComputedStyle(flexbox, null).justifyContent', '
 
 flexbox.style.justifyContent = '';
 shouldBeEqualToString('flexbox.style.justifyContent', '');
-shouldBeEqualToString('window.getComputedStyle(flexbox, null).justifyContent', 'flex-start');
+shouldBeEqualToString('window.getComputedStyle(flexbox, null).justifyContent', 'stretch');
 
 shouldBeEqualToString('flexbox.style.alignSelf', '');
 // The initial value is 'auto', which will be resolved depending on parent's style (except for the 'document' element).
@@ -167,8 +167,8 @@ shouldBeEqualToString('window.getComputedStyle(flexitem, null).alignSelf', 'stre
 
 flexbox.style.display = 'none';
 shouldBeEqualToString('flexbox.style.alignItems', '');
-shouldBeEqualToString('window.getComputedStyle(flexbox, null).alignItems', 'start');
-shouldBeEqualToString('window.getComputedStyle(flexitem, null).alignSelf', 'start');
+shouldBeEqualToString('window.getComputedStyle(flexbox, null).alignItems', 'auto');
+shouldBeEqualToString('window.getComputedStyle(flexitem, null).alignSelf', 'auto');
 flexbox.style.display = 'flex';