Add verbose logging for native accessibility events.

content/browser/accessibility/browser_accessibility_event.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_EVENT_H_
+#define CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_EVENT_H_
+
+#include <string>
+
+#include "content/browser/accessibility/browser_accessibility.h"
+#include "content/common/content_export.h"
+#include "ui/accessibility/ax_enums.h"
+
+namespace content {
+
+class BrowserAccessibility;
+
+class CONTENT_EXPORT BrowserAccessibilityEvent {
+ public:
+  enum Source {
+    FromBlink,
+    FromChildFrameLoading,
+    FromFindInPageResult,
+    FromRenderFrameHost,
+    FromScroll,
+    FromTreeChange,
+    FromWindowFocusChange,
+  };
+
+  enum Result {
+    Sent,
+    NotNeededOnThisPlatform,
+    DiscardedBecauseUserNavigatingAway,
+    DiscardedBecauseLiveRegionBusy,
+    FailedBecauseNoWindow,
+    FailedBecauseNoFocus,
+    FailedBecauseFrameIsDetached,
+  };
+
+  // Returns true if the given result indicates that sending the event failed.
+  // Returns false if the event was sent, or if it was not needed (which is
+  // not considered failure).
+  static bool FailedToSend(Result result);
+
+  static BrowserAccessibilityEvent* Create(Source source,
+                                           ui::AXEvent event_type,
+                                           const BrowserAccessibility* target);
+
+  // Construct a new accessibility event that should be sent via a
+  // platform-specific notification.
+  BrowserAccessibilityEvent(Source source,
+                            ui::AXEvent event_type,
+                            const BrowserAccessibility* target);
+  virtual ~BrowserAccessibilityEvent();
+
+  // Synchronously try to send the native accessibility event notification
+  // and return a result indicating the outcome. This deletes the event.
+  virtual Result Fire();
+
+  Source source() { return source_; }
+  ui::AXEvent event_type() { return event_type_; }
+  const BrowserAccessibility* target() { return target_; }
+  void set_target(const BrowserAccessibility* target) { target_ = target; }
+  void set_original_target(BrowserAccessibility* target) {
+    original_target_ = target;
+  }
+
+ protected:
+  virtual std::string GetEventNameStr();
+  void VerboseLog(Result result);
+
+ private:
+  Source source_;
+  ui::AXEvent event_type_;
+  const BrowserAccessibility* target_;
+  const BrowserAccessibility* original_target_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityEvent);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_EVENT_H_