Add private extension API to move the accessibility focus ring.

chrome/common/extensions/api/accessibility_private.json

Index: chrome/common/extensions/api/accessibility_private.json
diff --git a/chrome/common/extensions/api/accessibility_private.json b/chrome/common/extensions/api/accessibility_private.json
index bdc352024b8cad5d98347e2a6da195a3086b93df..d75353854b11419fe191ecbed828fff665d11d1f 100644
--- a/chrome/common/extensions/api/accessibility_private.json
+++ b/chrome/common/extensions/api/accessibility_private.json
@@ -159,6 +159,17 @@
             ]
           }
         }
+      },
+      {
+        "id": "ScreenRect",
+        "type": "object",
+        "description": "Bounding rectangle in global screen coordinates.",
+        "properties": {
+          "left": {"type": "integer", "description": "Left coordinate in global screen coordinates."},
+          "top": {"type": "integer", "description": "Top coordinate in global screen coordinates."},
+          "width": {"type": "integer", "description": "Width in pixels."},
+          "height": {"type": "integer", "description": "Height in pixels."}
+        }
       }
     ],
     "functions": [
@@ -228,6 +239,19 @@
             ]
           }
         ]
+      },
+      {
+        "name": "setFocusRing",
+        "type": "function",
+        "description": "Set the bounds of the accessibility focus ring.",
+        "parameters": [
+          {
+            "name": "rects",
+            "type": "array",
+            "items": { "$ref": "ScreenRect" },
+            "description": "Array of rectangles to focus."

[David Tseng, 2014/09/10 22:50:28]

This sounds like there would be a focus action taken upon a page. Do we simply
want to substitute "focus" with "indicator" everywhere to reduce
confusion/overloading?

[dmazzoni, 2014/09/11 22:04:36]

I clarified the text a bit.

I think it's clearer to call it an accessibility focus ring here rather than an
active indicator. The concept of focus and a focus ring is well-understood, it
makes it easier to understand and easier to read throughout the Chrome codebase.
Inside ChromeVox we use "active indicator" because we have to carefully track
keyboard focus and that's not always the same as the active element.

Another reason is that I intend to use the same code in Chrome OS to implement
support for a "highlight focused element" accessibility feature independent of
ChromeVox.

+          }
+        ]
       }
     ],
     "events": [