Fix infinite paint loop on Linux.

webkit/tools/test_shell/webwidget_host_gtk.cc

Index: webkit/tools/test_shell/webwidget_host_gtk.cc
diff --git a/webkit/tools/test_shell/webwidget_host_gtk.cc b/webkit/tools/test_shell/webwidget_host_gtk.cc
index b62f912f5c67b7e0d67b36b1236bfb9144644d40..d9769381c9f640d79d98b51e2adcdd97df3fdd2c 100644
--- a/webkit/tools/test_shell/webwidget_host_gtk.cc
+++ b/webkit/tools/test_shell/webwidget_host_gtk.cc
@@ -16,6 +16,8 @@
 
 namespace {
 
+bool handling_expose = false;
+
 // -----------------------------------------------------------------------------
 // Callback functions to proxy to host...
 
@@ -27,9 +29,11 @@ gboolean ConfigureEvent(GtkWidget* widget, GdkEventConfigure* config,
 
 gboolean ExposeEvent(GtkWidget* widget, GdkEventExpose* expose,
                      WebWidgetHost* host) {
+  handling_expose = true;
   gfx::Rect rect(expose->area);
   host->UpdatePaintRect(rect);
   host->Paint();
+  handling_expose = false;
   return FALSE;
 }
 
@@ -155,8 +159,10 @@ void WebWidgetHost::DidInvalidateRect(const gfx::Rect& damaged_rect) {
 
   UpdatePaintRect(damaged_rect);
 
-  gtk_widget_queue_draw_area(GTK_WIDGET(view_), damaged_rect.x(),
-      damaged_rect.y(), damaged_rect.width(), damaged_rect.height());
+  if (!handling_expose) {
+    gtk_widget_queue_draw_area(GTK_WIDGET(view_), damaged_rect.x(),
+        damaged_rect.y(), damaged_rect.width(), damaged_rect.height());
+  }
 }
 
 void WebWidgetHost::DidScrollRect(int dx, int dy, const gfx::Rect& clip_rect) {