Remove WebGLObject maps from WebGLRenderingContextBase and WebGLContextGroup.

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

 /*
  * Copyright (C) 2009 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 29 matching lines @@
       m_linkStatus(false),
       m_linkCount(0),
       m_activeTransformFeedbackCount(0),
       m_vertexShader(this, nullptr),
       m_fragmentShader(this, nullptr),
       m_infoValid(true) {
   setObject(ctx->contextGL()->CreateProgram());
 }
 
 WebGLProgram::~WebGLProgram() {
-  // These heap objects handle detachment on their own. Clear out
-  // the references to prevent deleteObjectImpl() from trying to do
-  // same, as we cannot safely access other heap objects from this
-  // destructor.
-  m_vertexShader = nullptr;
-  m_fragmentShader = nullptr;
-
-  // See the comment in WebGLObject::detachAndDeleteObject().
-  detachAndDeleteObject();
+  runDestructor();
 }
 
 void WebGLProgram::deleteObjectImpl(gpu::gles2::GLES2Interface* gl) {
   gl->DeleteProgram(m_object);
   m_object = 0;
-  if (m_vertexShader) {
-    m_vertexShader->onDetached(gl);
-    m_vertexShader = nullptr;
-  }
-  if (m_fragmentShader) {
-    m_fragmentShader->onDetached(gl);
-    m_fragmentShader = nullptr;
+  if (!destructionInProgress()) {

[Kai Ninomiya, 2016/12/02 18:51:28]

Does this depend on the assumption that there is only one context per share
group? In theory, if there were multiple contexts per share group, could this
cause a GL resource leak?

[Ken Russell (switch to Gerrit), 2016/12/02 20:38:49]

No, no such assumption and no such leak. When the WebGLShaders themselves are
GC'd, they will call detachAndDelete in their destructor, which will delete
their shader objects.

+    if (m_vertexShader) {
+      m_vertexShader->onDetached(gl);
+      m_vertexShader = nullptr;
+    }
+    if (m_fragmentShader) {
+      m_fragmentShader->onDetached(gl);
+      m_fragmentShader = nullptr;
+    }
   }
 }
 
 bool WebGLProgram::linkStatus(WebGLRenderingContextBase* context) {
   cacheInfoIfNeeded(context);
   return m_linkStatus;
 }
 
 void WebGLProgram::increaseLinkCount() {
   ++m_linkCount;
@@ skipping 83 matching lines @@
   WebGLSharedPlatform3DObject::trace(visitor);
 }
 
 DEFINE_TRACE_WRAPPERS(WebGLProgram) {
   visitor->traceWrappers(m_vertexShader);
   visitor->traceWrappers(m_fragmentShader);
   WebGLSharedPlatform3DObject::traceWrappers(visitor);
 }
 
 }  // namespace blink