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

content/renderer/render_view_impl.cc

Index: content/renderer/render_view_impl.cc
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index e29914ad8ba78a2da4a9e772aca9f33d18e41cf7..70609451e6a51918d8170ab825799ee37c8a3a00 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -685,6 +685,8 @@ void RenderViewImpl::Initialize(RenderViewImplParams* params) {
 #else
   notification_provider_ = NULL;
 #endif
+  renderer_preferences_.allow_partial_swap =
+      params->renderer_prefs.allow_partial_swap;

[alexst (slow to review), 2013/03/07 00:33:41]

This needs to be set here because OnSetRendererPrefs relies on webwidget_ being
initialized, and we need to know if we are partially swapping during webwidget_
initialization.

[jamesr, 2013/03/07 00:48:06]

Hmmmm, this is getting quite tricky.  Why don't you just set this in the
constructor?

Rather than being a RendererPreference that's actually slightly magical, what
about making this a CreateWindow_Params member and putting it explicitly in the
RenderViewImplParams struct?

 
   webwidget_ = WebView::create(this);
   webwidget_mouse_lock_target_.reset(new WebWidgetLockTarget(webwidget_));
@@ -6285,6 +6287,10 @@ void RenderViewImpl::InstrumentWillComposite() {
   webview()->devToolsAgent()->willComposite();
 }
 
+bool RenderViewImpl::AllowPartialSwap() const {
+  return renderer_preferences_.allow_partial_swap;
+}
+
 #if defined(OS_WIN)
 void RenderViewImpl::PluginFocusChanged(bool focused, int plugin_id) {
   if (focused)