Implement automatic load of composed/embedded automation trees

chrome/browser/extensions/api/automation_internal/automation_internal_api.cc

Index: chrome/browser/extensions/api/automation_internal/automation_internal_api.cc
diff --git a/chrome/browser/extensions/api/automation_internal/automation_internal_api.cc b/chrome/browser/extensions/api/automation_internal/automation_internal_api.cc
index 40e184bbf3b64d5776b523af8abb94ca9feb063d..acac0b48bb2cad668aa32df4337d441ebd9e6f6f 100644
--- a/chrome/browser/extensions/api/automation_internal/automation_internal_api.cc
+++ b/chrome/browser/extensions/api/automation_internal/automation_internal_api.cc
@@ -17,6 +17,7 @@
 #include "chrome/common/extensions/api/automation_internal.h"
 #include "chrome/common/extensions/manifest_handlers/automation.h"
 #include "content/public/browser/ax_event_notification_details.h"
+#include "content/public/browser/browser_accessibility_state.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_widget_host.h"
@@ -167,7 +168,26 @@ AutomationInternalEnableTabFunction::Run() {
   return RespondNow(
       ArgumentList(api::automation_internal::EnableTab::Results::Create(
           rfh->GetProcess()->GetID(), rfh->GetRoutingID())));
-  }
+}
+
+ExtensionFunction::ResponseAction
+AutomationInternalEnableFrameFunction::Run() {
+  using api::automation_internal::EnableFrame::Params;
+  scoped_ptr<Params> params(Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params.get());
+  content::RenderFrameHost* rfh =
+      content::RenderFrameHost::FromID(params->process_id,
+                                       params->routing_id);
+  if (!rfh)
+    return RespondNow(Error("unable to load tab"));
+
+  content::WebContents* contents =
+      content::WebContents::FromRenderFrameHost(rfh);
+  AutomationWebContentsObserver::CreateForWebContents(contents);
+  contents->EnableTreeOnlyAccessibilityMode();
+
+  return RespondNow(NoArguments());
+}
 
 ExtensionFunction::ResponseAction
 AutomationInternalPerformActionFunction::Run() {