Merge 89635 - 2011-06-23 John Bates <jbates@google.com>

Source/WebCore/platform/graphics/chromium/WebGLLayerChromium.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 43 matching lines @@
     , m_textureUpdated(false)
 {
 }
 
 WebGLLayerChromium::~WebGLLayerChromium()
 {
     if (m_context && layerRenderer())
         layerRenderer()->removeChildContext(m_context);
 }
 
+bool WebGLLayerChromium::drawsContent() const
+{
+    return (m_context && m_context->getExtensions()->getGraphicsResetStatusARB() == GraphicsContext3D::NO_ERROR);
+}
+
 void WebGLLayerChromium::updateCompositorResources()
 {
-    if (!m_context)
+    if (!drawsContent())
         return;
 
     if (!m_contentsDirty)
         return;
 
     GraphicsContext3D* rendererContext = layerRendererContext();
     if (m_textureChanged) {
         rendererContext->bindTexture(GraphicsContext3D::TEXTURE_2D, m_textureId);
         // Set the min-mag filters to linear and wrap modes to GL_CLAMP_TO_EDGE
         // to get around NPOT texture limitations of GLES.
@@ skipping 19 matching lines @@
 {
     m_textureUpdated = true;
     // If WebGL commands are issued outside of a the animation callbacks, then use
     // call rateLimitOffscreenContextCHROMIUM() to keep the context from getting too far ahead.
     if (layerRenderer() && !layerRenderer()->isAnimating() && m_contextSupportsRateLimitingExtension && !m_rateLimitingTimer.isActive())
         m_rateLimitingTimer.startOneShot(0);
 }
 
 void WebGLLayerChromium::setContext(const GraphicsContext3D* context)
 {
-    if (m_context != context && layerRenderer()) {
+    bool contextChanged = (m_context != context);
+    if (contextChanged && layerRenderer()) {
         if (m_context)
             layerRenderer()->removeChildContext(m_context);
         if (context)
             layerRenderer()->addChildContext(const_cast<GraphicsContext3D*>(context));
     }
 
     m_context = const_cast<GraphicsContext3D*>(context);
 
     if (!m_context)
         return;
 
     unsigned int textureId = m_context->platformTexture();
-    if (textureId != m_textureId) {
+    if (textureId != m_textureId || contextChanged) {
         m_textureChanged = true;
         m_textureUpdated = true;
     }
     m_textureId = textureId;
     GraphicsContext3D::Attributes attributes = m_context->getContextAttributes();
     m_hasAlpha = attributes.alpha;
     m_premultipliedAlpha = attributes.premultipliedAlpha;
     m_contextSupportsRateLimitingExtension = m_context->getExtensions()->supports("GL_CHROMIUM_rate_limit_offscreen_context");
 }
 
@@ skipping 17 matching lines @@
 
     if (!m_context)
         return;
 
     Extensions3DChromium* extensions = static_cast<Extensions3DChromium*>(m_context->getExtensions());
     extensions->rateLimitOffscreenContextCHROMIUM();
 }
 
 }
 #endif // USE(ACCELERATED_COMPOSITING)