Revert 135593 - Add initial GTK web accessibility framework (new with valgrind fix).

content/browser/accessibility/browser_accessibility_manager.cc

Index: content/browser/accessibility/browser_accessibility_manager.cc
===================================================================
--- content/browser/accessibility/browser_accessibility_manager.cc	(revision 135594)
+++ content/browser/accessibility/browser_accessibility_manager.cc	(working copy)
@@ -21,11 +21,9 @@
 // static
 int32 BrowserAccessibilityManager::next_child_id_ = -1;
 
-#if !defined(OS_MACOSX) && \
-    !(defined(OS_WIN) && !defined(USE_AURA)) && \
-    !defined(TOOLKIT_GTK)
-// We have subclassess of BrowserAccessibilityManager on Mac, Linux/GTK,
-// and non-Aura Win. For any other platform, instantiate the base class.
+#if (defined(OS_POSIX) && !defined(OS_MACOSX)) || defined(USE_AURA)
+// There's no OS-specific implementation of BrowserAccessibilityManager
+// on Unix, so just instantiate the base class.
 // static
 BrowserAccessibilityManager* BrowserAccessibilityManager::Create(
     gfx::NativeView parent_view,