Remove WebGLObject maps from WebGLRenderingContextBase and WebGLContextGroup.

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

Index: third_party/WebKit/Source/modules/webgl/WebGLProgram.cpp
diff --git a/third_party/WebKit/Source/modules/webgl/WebGLProgram.cpp b/third_party/WebKit/Source/modules/webgl/WebGLProgram.cpp
index e75362f0fb60bab485e661aa5678587ef35aea74..2857fb2893f54f13e49f0ddde583954133ef593d 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGLProgram.cpp
+++ b/third_party/WebKit/Source/modules/webgl/WebGLProgram.cpp
@@ -47,27 +47,21 @@ WebGLProgram::WebGLProgram(WebGLRenderingContextBase* ctx)
 }
 
 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;
+    }
   }
 }