check for null-device before using the windowless canvas

content/plugin/webplugin_proxy.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/plugin/webplugin_proxy.h"
 
 #include "build/build_config.h"
 
 #include "base/bind.h"
 #include "base/lazy_instance.h"
@@ skipping 321 matching lines @@
   params.notify_redirects = notify_redirects;
 
   Send(new PluginHostMsg_URLRequest(route_id_, params));
 }
 
 void WebPluginProxy::Paint(const gfx::Rect& rect) {
 #if defined(OS_MACOSX)
   if (!windowless_context())
     return;
 #else
-  if (!windowless_canvas())
+  if (!windowless_canvas() || !windowless_canvas()->getDevice())
     return;
 #endif
 
   // Clear the damaged area so that if the plugin doesn't paint there we won't
   // end up with the old values.
   gfx::Rect offset_rect = rect;
   offset_rect.Offset(delegate_->GetRect().origin());
 #if defined(OS_MACOSX)
   CGContextSaveGState(windowless_context());
   // It is possible for windowless_contexts_ to change during plugin painting
@@ skipping 30 matching lines @@
   windowless_canvas()->save();
 
   // The given clip rect is relative to the plugin coordinate system.
   SkRect sk_rect = { SkIntToScalar(rect.x()),
                      SkIntToScalar(rect.y()),
                      SkIntToScalar(rect.right()),
                      SkIntToScalar(rect.bottom()) };
   windowless_canvas()->clipRect(sk_rect);
 
   // Setup the background.
-  if (background_canvas_.get()) {
+  if (background_canvas_.get() && background_canvas_.get()->getDevice()) {
     // When a background canvas is given, we're in transparent mode. This means
     // the plugin wants to have the image of the page in the canvas it's drawing
     // into (which is windowless_canvases_) so it can do blending. So we copy
     // the background bitmap into the windowless canvas.
     const SkBitmap& background_bitmap =
         skia::GetTopDevice(*background_canvas_)->accessBitmap(false);
     windowless_canvas()->drawBitmap(background_bitmap, 0, 0);
   } else {
     // In non-transparent mode, the plugin doesn't care what's underneath, so we
     // can just give it black.
@@ skipping 371 matching lines @@
   // Retrieve the IME status from a plug-in and send it to a renderer process
   // when the plug-in has updated it.
   int input_type;
   gfx::Rect caret_rect;
   if (!delegate_->GetIMEStatus(&input_type, &caret_rect))
     return;
 
   Send(new PluginHostMsg_NotifyIMEStatus(route_id_, input_type, caret_rect));
 }
 #endif