[WebLayer] Fix text in long-press context menu

Some of the menu items were showing up as @<id> because the wrong
Resources were used to resolve IDs from the menu. This is fixed by
overriding getTheme() if we have a resources override context, so
anybody who uses the resources from the theme will get the correct
object.

Bug: 1046158
Change-Id: I3e22f385ba01eb5cc9bc49c7cf9d98e98386ccf7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2024151Reviewed-by: Bo <boliu@chromium.org>
Commit-Queue: Clark DuVall <cduvall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#735758}

components/embedder_support/android/java/src/org/chromium/components/embedder_support/application/ClassLoaderContextWrapperFactory.java

@@ -151,5 +151,13 @@ public class ClassLoaderContextWrapperFactory {
             }
             return getBaseContext().getResources();
         }
+
+        @Override
+        public Resources.Theme getTheme() {
+            if (sResourceOverrideContext != null) {
+                return sResourceOverrideContext.getTheme();
+            }
+            return getBaseContext().getTheme();
+        }
     }
 }