Make it more obvious when our backing store has failed us.

chrome/browser/renderer_host/render_widget_host_view_gtk.cc

Index: chrome/browser/renderer_host/render_widget_host_view_gtk.cc
diff --git a/chrome/browser/renderer_host/render_widget_host_view_gtk.cc b/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
index 08c0d4fef8b9c680c7340b95fbc47066e202e92c..4bc769cdddb95424724a4f827d89a921da12b9bf 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
+++ b/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
@@ -9,6 +9,7 @@
 #include <cairo/cairo.h>
 
 #include "base/logging.h"
+#include "base/gfx/gtk_util.h"
 #include "base/string_util.h"
 #include "chrome/common/native_web_keyboard_event.h"
 #include "chrome/common/x11_util.h"
@@ -340,16 +341,28 @@ BackingStore* RenderWidgetHostViewGtk::AllocBackingStore(
 void RenderWidgetHostViewGtk::Paint(const gfx::Rect& damage_rect) {
   BackingStore* backing_store = host_->GetBackingStore();
 
+  GdkWindow* window = view_.get()->window;
   if (backing_store) {
     // Only render the widget if it is attached to a window; there's a short
     // period where this object isn't attached to a window but hasn't been
     // Destroy()ed yet and it receives paint messages...
-    GdkWindow* window = view_.get()->window;
     if (window) {
       backing_store->ShowRect(
           damage_rect, x11_util::GetX11WindowFromGtkWidget(view_.get()));
     }
   } else {
+    if (window) {
+      // Set the window background to sea foam green.
+      if (!gfx::kGdkSeafoamGreen.pixel) {
+        // We need the color "allocated" to use for the window background.
+        gdk_colormap_alloc_color(gdk_colormap_get_system(),
+                                 &gfx::kGdkSeafoamGreen,
+                                 FALSE /* not writable */,
+                                 TRUE /* best match */);
+      }
+      gdk_window_set_background(window, &gfx::kGdkSeafoamGreen);
+      gdk_window_clear(window);
+    }
     NOTIMPLEMENTED();
   }
 }