Make Smart Lock user pod icons work well with ChromeVox.

chrome/browser/signin/screenlock_bridge.h

Index: chrome/browser/signin/screenlock_bridge.h
diff --git a/chrome/browser/signin/screenlock_bridge.h b/chrome/browser/signin/screenlock_bridge.h
index 7add894433c7839b18595bee23efd05872e83452..c9b702db85273701363d1db32e5770408227f0ad 100644
--- a/chrome/browser/signin/screenlock_bridge.h
+++ b/chrome/browser/signin/screenlock_bridge.h
@@ -64,6 +64,10 @@ class ScreenlockBridge {
     // shown with the icon.
     void SetTooltip(const base::string16& tooltip, bool autoshow);
 
+    // Sets the accessiblity label of the icon. If this attribute is not
+    // provided, then the tooltip will be used.
+    void SetAriaLabel(const base::string16& aria_label);
+
     // If hardlock on click is set, clicking the icon in the screenlock will
     // go to state where password is required for unlock.
     void SetHardlockOnClick();
@@ -74,6 +78,8 @@ class ScreenlockBridge {
     base::string16 tooltip_;
     bool autoshow_tooltip_;
 
+    base::string16 aria_label_;
+
     bool hardlock_on_click_;
 
     DISALLOW_COPY_AND_ASSIGN(UserPodCustomIconOptions);