nit: Use Title Case for "Select All" in views::Textfield context menus on Mac.

ui/strings/ui_strings.grd

Index: ui/strings/ui_strings.grd
diff --git a/ui/strings/ui_strings.grd b/ui/strings/ui_strings.grd
index 61de22536c1791956a41c23ce3de96247008cae4..0cf9f04ff38647ea4578d8048c128682aab6d8f9 100644
--- a/ui/strings/ui_strings.grd
+++ b/ui/strings/ui_strings.grd
@@ -413,9 +413,16 @@ need to be translated for each locale.-->
       <message name="IDS_APP_DELETE" desc="The text label of the Delete menu item">
         &amp;Delete
       </message>
-      <message name="IDS_APP_SELECT_ALL" desc="The text label of the Select All menu item">
-        Select &amp;all
-      </message>
+      <if expr="not use_titlecase">
+        <message name="IDS_APP_SELECT_ALL" desc="The text label of the Select All menu item">
+          Select &amp;all
+        </message>
+      </if>
+      <if expr="use_titlecase">
+        <message name="IDS_APP_SELECT_ALL" desc="In Title Case: The text label of the Select All menu item">
+          Select &amp;All
+        </message>
+      </if>
 
       <!-- Generic terms -->
       <message name="IDS_APP_OK" desc="Used for Ok on buttons">