MD Settings: convert paper-icon-button to paper-icon-button-light.

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 f80a70d076c497d5241f99bf7be66ba89c2f9556..78fc99a30a45cef424fe30b6cfd613589d00b5a7 100644
--- a/chrome/browser/resources/settings/settings_shared_css.html
+++ b/chrome/browser/resources/settings/settings_shared_css.html
@@ -320,6 +320,17 @@
         outline: none;
       }
 
+      /* Prevent icon-button's ripples from fighting with potential scrollbars.
+       * Also apply to all iron-lists to align the buttons across them all.*/
+      [scrollable],
+      .scroll-container,
+      iron-list {
+        --cr-paper-icon-button-margin: {
+          -webkit-margin-start: 0;
+          -webkit-margin-end: 0;
+        };
+      }
+
       /* Helper for a list frame to automatically avoid the separator line. */
       .vertical-list > *:not(:first-of-type) {
         border-top: var(--settings-separator-line);
@@ -343,6 +354,14 @@
             2 * var(--settings-separator-gaps));
       }
 
+
+      /* Avoid too much margin from both .separator and the button */
+      .separator + button[is='paper-icon-button-light'] {
+        --cr-paper-icon-button-margin: {
+          --webkit-margin-start: 0;
+        };
+      }
+
       .settings-checkbox-spacer {
         -webkit-margin-start: calc(
             var(--checkbox-margin-start) +