Fix display and progressive disclosure for multi-line values in about:policy.

chrome/browser/resources/policy.css

Index: chrome/browser/resources/policy.css
diff --git a/chrome/browser/resources/policy.css b/chrome/browser/resources/policy.css
index ba436341042dd3258dd316d40f9931ce7440463f..81f53856e65dafc94e8cd0ca40a97fa8d0ad1983 100644
--- a/chrome/browser/resources/policy.css
+++ b/chrome/browser/resources/policy.css
@@ -136,24 +136,45 @@ legend {
 
 #policy-table td {
   background-color: #eaeef3;
-  overflow: hidden;
   padding: 10px;
-  text-overflow: ellipsis;
+  position: relative;
+  vertical-align: top;
   width: 20%;
 }
 
-.toggler {
-  color: #808080;
-  cursor: pointer;
+.text-collapsed {
+  bottom: 0;
+  left: 0;
+  margin: 10px;
+  overflow: hidden;
+  position: absolute;
+  right: 0;
+  top: 0;
 }
 
-.collapsed {
+.text-cell {
   overflow: hidden;
+}
+
+.text-collapsed .text-cell {
   text-overflow: ellipsis;
-  white-space: nowrap;
 }
 
-.expanded {
+.text-expanded .text-cell {
   overflow: visible;
   word-wrap: break-word;
 }
+
+.text-collapsed .text-value {
+  white-space: nowrap;
+}
+
+.text-expanded .text-value {
+  white-space: pre-wrap;
+}
+
+.toggler {
+  color: #808080;
+  cursor: pointer;
+  float: right;
+}