[MD settings] css for row separator

chrome/browser/resources/settings/settings_shared_css.html

Index: chrome/browser/resources/settings/settings_shared_css.html
diff --git a/chrome/browser/resources/settings/settings_shared_css.html b/chrome/browser/resources/settings/settings_shared_css.html
index 5204d00657ace2e0ebd7cd40148354e81fa2a4e5..18d9d504b3e8f915c3752d70d0ccaae1600fb09b 100644
--- a/chrome/browser/resources/settings/settings_shared_css.html
+++ b/chrome/browser/resources/settings/settings_shared_css.html
@@ -318,8 +318,8 @@
         outline: none;
       }
 
-      /* The secondary-action wraps a clickable sub-area of a .settings-box.
-       * An example is the |sign out| button on the People settings.
+      /* TODO(dschuyler): replace with .separator.
+       * The secondary-action wraps a clickable sub-area of a .settings-box.
        * Here is an example with and without a secondary action box:
        *
        *  +-------------------------------------------------------+
@@ -346,6 +346,24 @@
         border-top: var(--settings-separator-line);
       }
 
+      /* The vertical-rule-line is a separator line like a horizontal rule

[Dan Beam, 2017/05/01 15:32:31]

can you update this comment?

[dschuyler, 2017/05/01 19:26:11]

Done.

+       * <hr> tag, but goes the other way.
+       * An example is near the |sign out| button on the People settings. */
+      :-webkit-any(.settings-box, .list-item) .separator {
+        -webkit-border-start: var(--settings-separator-line);
+        -webkit-margin-start: var(--settings-box-row-padding);
+        -webkit-padding-start: var(--settings-box-row-padding);

[Dan Beam, 2017/05/01 15:32:31]

is there a reason we have to use padding instead of margin-end?

[dschuyler, 2017/05/01 19:26:11]

There used to be (when the div had contents), but that no longer applies.

Done.

+        flex-shrink: 0;
+        --settings-separator-gaps: 9px;

[Dan Beam, 2017/05/01 15:32:31]

so wait, does this mean 4.5px on top and bottom? do we want an even number?

[dschuyler, 2017/05/01 19:26:11]

The numbers bettes@ asked for is 45px row with a 36px vertical line. It looks
good in practice because the half px allows for an anit-aliasing tapering of the
tips. I'd question Alan further on it if it looked wrong, but it looks fine imo.

+        height: calc(var(--settings-row-min-height) -
+            var(--settings-separator-gaps));
+      }
+
+      :-webkit-any(.settings-box, .list-item).two-line .separator {
+        height: calc(var(--settings-row-two-line-min-height) -
+            2 * var(--settings-separator-gaps));

[Dan Beam, 2017/05/01 15:32:31]

why is this doubled in this case?

[dschuyler, 2017/05/01 19:26:11]

This is from an aesthetic call by UI (bettes@): on a 64px row the grey line
should be 56px. This could also be done with a separate variable like
--settings-two-line-separator-gaps: 18px.

+      }
+
       .settings-checkbox-spacer {
         -webkit-margin-start: calc(
             var(--checkbox-margin-start) +