Remove WebGLObject maps from WebGLRenderingContextBase and WebGLContextGroup.

third_party/WebKit/Source/modules/webgl/WebGLContextObject.cpp

 /*
  * Copyright (C) 2011 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 14 matching lines @@
 
 #include "modules/webgl/WebGLContextObject.h"
 
 #include "modules/webgl/WebGLRenderingContextBase.h"
 
 namespace blink {
 
 WebGLContextObject::WebGLContextObject(WebGLRenderingContextBase* context)
     : WebGLObject(context), m_context(context) {}
 
-WebGLContextObject::~WebGLContextObject() {}
+bool WebGLContextObject::validate(
+    const WebGLContextGroup*,
+    const WebGLRenderingContextBase* context) const {
+  // The contexts and context groups no longer maintain references to all
+  // the objects they ever created, so there's no way to invalidate them
+  // eagerly during context loss. The invalidation is discovered lazily.
+  return context == m_context &&
+         cachedNumberOfContextLosses() == context->numberOfContextLosses();
+}
 
-void WebGLContextObject::detachContext() {
-  detach();
-  if (m_context) {
-    deleteObject(m_context->contextGL());
-    m_context->removeContextObject(this);
-    m_context = nullptr;
-  }
+uint32_t WebGLContextObject::currentNumberOfContextLosses() const {
+  return m_context->numberOfContextLosses();
 }
 
 gpu::gles2::GLES2Interface* WebGLContextObject::getAGLInterface() const {
   return m_context->contextGL();
 }
 
 DEFINE_TRACE(WebGLContextObject) {
   visitor->trace(m_context);
   WebGLObject::trace(visitor);
 }
 
 }  // namespace blink