GTK: add more syncronization to GtkNativeViewIdManager to avoid a crash.

BUG=46197
TEST=manual (see bug)

Review URL: http://codereview.chromium.org/2860024

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@50886 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 13 insertions, 4 deletions

diff --git a/gfx/gtk_native_view_id_manager.cc b/gfx/gtk_native_view_id_manager.cc
index 47dc2fb..91407283a 100644
--- a/gfx/gtk_native_view_id_manager.cc
+++ b/gfx/gtk_native_view_id_manager.cc
@@ -116,6 +116,7 @@ void GtkNativeViewManager::OnRealize(gfx::NativeView widget) {
 }
 
 void GtkNativeViewManager::OnUnrealize(gfx::NativeView widget) {
+  AutoLock unrealize_locked(unrealize_lock_);
   AutoLock locked(lock_);
 
   const gfx::NativeViewId id = GetWidgetId(widget);
diff --git a/gfx/gtk_native_view_id_manager.h b/gfx/gtk_native_view_id_manager.h
index 048cd2d..3a23942 100644
--- a/gfx/gtk_native_view_id_manager.h
+++ b/gfx/gtk_native_view_id_manager.h
@@ -63,6 +63,8 @@ class GtkNativeViewManager {
   void OnUnrealize(gfx::NativeView widget);
   void OnDestroy(gfx::NativeView widget);
 
+  Lock& unrealize_lock() { return unrealize_lock_; }
+
  private:
   // This object is a singleton:
   GtkNativeViewManager();
@@ -78,12 +80,18 @@ class GtkNativeViewManager {
 
   gfx::NativeViewId GetWidgetId(gfx::NativeView id);
 
+  // This lock can be used to block GTK from unrealizing windows. This is needed
+  // when the BACKGROUND_X11 thread is using a window obtained via GetXIDForId,
+  // and can't allow the X11 resource to be deleted.
+  Lock unrealize_lock_;
+
   // protects native_view_to_id_ and id_to_info_
   Lock lock_;
-    // If asked for an id for the same widget twice, we want to return the same
-    // id. So this records the current mapping.
-    std::map<gfx::NativeView, gfx::NativeViewId> native_view_to_id_;
-    std::map<gfx::NativeViewId, NativeViewInfo> id_to_info_;
+
+  // If asked for an id for the same widget twice, we want to return the same
+  // id. So this records the current mapping.
+  std::map<gfx::NativeView, gfx::NativeViewId> native_view_to_id_;
+  std::map<gfx::NativeViewId, NativeViewInfo> id_to_info_;
 
   DISALLOW_COPY_AND_ASSIGN(GtkNativeViewManager);
 };