Add support for retrieving image thumbnails as part of the accessibility tree.

chrome/common/extensions/api/automation.idl

Index: chrome/common/extensions/api/automation.idl
diff --git a/chrome/common/extensions/api/automation.idl b/chrome/common/extensions/api/automation.idl
index 451fc942084478c1c37db561258636b91be49b00..5fcaba56d1d93a02c467c8162e7cbe92ba0840dd 100644
--- a/chrome/common/extensions/api/automation.idl
+++ b/chrome/common/extensions/api/automation.idl
@@ -24,6 +24,7 @@
     documentSelectionChanged,
     expandedChanged,
     focus,
+    imageFrameUpdated,
     hide,
     hover,
     invalidStatusChanged,
@@ -575,6 +576,9 @@
     // Places focus on this node.
     static void focus();
 
+    // Request a data url for the contents of an image.
+    static void getImageData(long maxWidth, long maxHeight);

[aboxhall, 2016/11/22 19:06:31]

As discussed, please clarify how to return original dimensions.

[dmazzoni, 2016/11/22 22:00:13]

Done.

+
     // Scrolls this node to make it visible.
     static void makeVisible();