Return additional info in WebPrintPresetOptions:

public/web/WebPrintPresetOptions.h

Index: public/web/WebPrintPresetOptions.h
diff --git a/public/web/WebPrintPresetOptions.h b/public/web/WebPrintPresetOptions.h
index ff7881643fb15d499d3d5e0490e3522a8ab53db2..7c7506c3dc776f894b8db102a53ecc6e82232864 100644
--- a/public/web/WebPrintPresetOptions.h
+++ b/public/web/WebPrintPresetOptions.h
@@ -41,6 +41,12 @@ struct WebPrintPresetOptions {
 
     // Specifies page range to be used for printing.
     WebPageRanges pageRanges;
+
+    // True if all the pages in the PDF are the same size.
+    bool isPageSizeUniform;
+
+    // Only valid if the page sizes are uniform. The page size in points.
+    WebSize uniformPageSize;
 };
 
 } // namespace blink