Add the Mac OSX Keychain message to the Passwords Page.

chrome/app/settings_strings.grdp

Index: chrome/app/settings_strings.grdp
diff --git a/chrome/app/settings_strings.grdp b/chrome/app/settings_strings.grdp
index a98e06ee0af042392d2c060a1541e5b98fb462e7..c7d4e772952ccabfc524a61f00ab3d176a76bca4 100644
--- a/chrome/app/settings_strings.grdp
+++ b/chrome/app/settings_strings.grdp
@@ -261,9 +261,18 @@
   <message name="IDS_SETTINGS_PASSWORDS_PASSWORD" desc="Label for the saved password when editing a password.">
     Password
   </message>
-  <message name="IDS_SETTINGS_PASSWORDS_MANAGE_PASSWORDS" desc="Shown in the passwords section of settings. Descriptive text to inform that passwords can be accessed online. Has a link.">
-    Access your passwords from any device at <ph name="BEGIN_LINK">&lt;a is="action-link" href="$1" target="_blank"&gt;</ph>passwords.google.com<ph name="END_LINK">&lt;/a&gt;</ph>
-  </message>
+  <if expr="is_macosx">
+    <then>
+      <message name="IDS_SETTINGS_PASSWORDS_MANAGE_PASSWORDS" desc="Shown in the passwords section of settings. Descriptive text to inform that passwords can be accessed online. Has a link. Also notifies mac users that chrome will sync passwords to the OS's Keychain, so their passwords will be synced to other chrome profiles.">
+        Access your passwords from any device at <ph name="BEGIN_LINK">&lt;a is="action-link" href="$1" target="_blank"&gt;</ph>passwords.google.com<ph name="END_LINK">&lt;/a&gt;</ph>. On Mac, passwords may be saved to your Keychain and accessed or synced by other Chrome users sharing this OS X account.
+      </message>
+    </then>
+    <else>
+      <message name="IDS_SETTINGS_PASSWORDS_MANAGE_PASSWORDS" desc="Shown in the passwords section of settings. Descriptive text to inform that passwords can be accessed online. Has a link.">
+        Access your passwords from any device at <ph name="BEGIN_LINK">&lt;a is="action-link" href="$1" target="_blank"&gt;</ph>passwords.google.com<ph name="END_LINK">&lt;/a&gt;</ph>
+      </message>
+    </else>
+  </if>
 
   <!-- Default Browser Page -->
   <if expr="not chromeos">