Implement accessibility support for CSS-transformed iframes.

content/browser/accessibility/browser_accessibility_manager.h

Index: content/browser/accessibility/browser_accessibility_manager.h
diff --git a/content/browser/accessibility/browser_accessibility_manager.h b/content/browser/accessibility/browser_accessibility_manager.h
index 908029b5708399d529f3a6d9ff207727e3f0b23c..4b98622766d072f3e8e8fb668499966a89f70837 100644
--- a/content/browser/accessibility/browser_accessibility_manager.h
+++ b/content/browser/accessibility/browser_accessibility_manager.h
@@ -35,6 +35,8 @@ class BrowserAccessibilityManagerWin;
 class BrowserAccessibilityManagerAuraLinux;
 #endif
 
+class SiteInstance;
+
 // For testing.
 CONTENT_EXPORT ui::AXTreeUpdate MakeAXTreeUpdate(
     const ui::AXNodeData& node,
@@ -79,6 +81,9 @@ class CONTENT_EXPORT BrowserAccessibilityDelegate {
   virtual gfx::Rect AccessibilityGetViewBounds() const = 0;
   virtual gfx::Point AccessibilityOriginInScreen(
       const gfx::Rect& bounds) const = 0;
+  virtual gfx::Rect AccessibilityTransformToRootCoordSpace(
+      const gfx::Rect& bounds) = 0;

[dcheng, 2016/03/23 05:26:00]

Part of me wonders if we really want this interface: it seems kind of like we
could just use TestRenderFrameHost for unit tests, since this code lives in
//content.

(Not really something to tackle in this patch, just wondering aloud)

[dmazzoni, 2016/03/24 04:26:53]

Yeah, the current design is that BrowserAccessibilityManager doesn't actually
depend on RFHI, it defines this delegate interface and RFHI depends on it.

It does seem like we could reverse the dependency and have this class depend on
RFHI instead. It's really only this way for historical reasons and I can see
pros and cons of both ways.

Maybe that's not exactly what you were asking.

For unit tests it does seem like we could use TestRenderFrameHost instead.

[dcheng, 2016/03/24 04:33:14]

This is basically along the lines of what I was thinking, but it's definitely a
project for another patch (if we do it at all).

+  virtual SiteInstance* AccessibilityGetSiteInstance() = 0;
   virtual void AccessibilityHitTest(
       const gfx::Point& point) = 0;
   virtual void AccessibilitySetAccessibilityFocus(int acc_obj_id) = 0;