Save image should download the original image when Data Saver is enabled.

chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ChromeContextMenuItemDelegate.java

Index: chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ChromeContextMenuItemDelegate.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ChromeContextMenuItemDelegate.java b/chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ChromeContextMenuItemDelegate.java
index fb15d2933e9eb0518e3799ae1886ac1507fb65e5..644c2902433b2dd6a62370f7586578c869b436a4 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ChromeContextMenuItemDelegate.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ChromeContextMenuItemDelegate.java
@@ -30,6 +30,13 @@ public interface ChromeContextMenuItemDelegate {
     boolean canLoadOriginalImage();
 
     /**
+     * Returns whether or not the Data Reduction Proxy is enabled for input url.
+     * @param url Input url to check for the Data Reduction Proxy setting.
+     * @return true if the Data Reduction Proxy is enabled for the url.
+    */
+    boolean isDataReductionProxyEnabledForURL(String url);
+
+    /**
      * Called when the context menu is trying to start a download.
      * @param url Url of the download item.
      * @param isLink Whether or not the download is a link (as opposed to an image/video).