Disable partial swaps for webview guest renderer until we can figure out how to do that properly.

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 6e81f97aa1e0935350f3bd82f7e9fbb31aa38852..6d6ec3966b6cde681ae236e2ef218100efbad59f 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -139,6 +139,7 @@ RenderWidget::RenderWidget(WebKit::WebPopupType popup_type,
       update_reply_pending_(false),
       need_update_rect_for_auto_resize_(false),
       using_asynchronous_swapbuffers_(false),
+      allow_partial_swap_(true),
       num_swapbuffers_complete_pending_(0),
       did_show_(false),
       is_hidden_(false),
@@ -1348,7 +1349,11 @@ void RenderWidget::initializeLayerTreeView(
     WebKit::WebLayerTreeViewClient* client,
     const WebKit::WebLayer& root_layer,
     const WebKit::WebLayerTreeView::Settings& settings) {
-  compositor_ = RenderWidgetCompositor::Create(this, client, settings);
+  WebKit::WebLayerTreeView::Settings override_settings = settings;
+  override_settings.partialSwapEnabled = allow_partial_swap_;
+  compositor_ = RenderWidgetCompositor::Create(this,
+                                               client,
+                                               override_settings);
   if (!compositor_)
     return;