Oilpan: move 2D Canvas and WebGL objects to the heap.

Source/core/html/canvas/WebGLRenderingContextBase.cpp

Index: Source/core/html/canvas/WebGLRenderingContextBase.cpp
diff --git a/Source/core/html/canvas/WebGLRenderingContextBase.cpp b/Source/core/html/canvas/WebGLRenderingContextBase.cpp
index 263027e76fd267a076d2db50fecf3470f27539d5..eb598d8afdaccf2653aa666aa904845134c7dede 100644
--- a/Source/core/html/canvas/WebGLRenderingContextBase.cpp
+++ b/Source/core/html/canvas/WebGLRenderingContextBase.cpp
@@ -92,6 +92,10 @@ const double secondsBetweenRestoreAttempts = 1.0;
 const int maxGLErrorsAllowedToConsole = 256;
 const unsigned maxGLActiveContexts = 16;
 
+// FIXME: Oilpan: static vectors to heap allocated WebGLRenderingContextBase objects
+// are kept here. This relies on the WebGLRenderingContextBase finalization to
+// explicitly retire themselves from these vectors, but it'd be preferable if
+// the references were traced as per usual.
 Vector<WebGLRenderingContextBase*>& WebGLRenderingContextBase::activeContexts()
 {
     DEFINE_STATIC_LOCAL(Vector<WebGLRenderingContextBase*>, activeContexts, ());
@@ -224,6 +228,7 @@ public:
 namespace {
 
     class ScopedDrawingBufferBinder {
+        STACK_ALLOCATED();
     public:
         ScopedDrawingBufferBinder(DrawingBuffer* drawingBuffer, WebGLFramebuffer* framebufferBinding)
             : m_drawingBuffer(drawingBuffer)
@@ -243,7 +248,7 @@ namespace {
 
     private:
         DrawingBuffer* m_drawingBuffer;
-        WebGLFramebuffer* m_framebufferBinding;
+        RawPtrWillBeMember<WebGLFramebuffer> m_framebufferBinding;
     };
 
     Platform3DObject objectOrZero(WebGLObject* object)
@@ -468,8 +473,9 @@ namespace {
 } // namespace anonymous
 
 class ScopedTexture2DRestorer {
+    STACK_ALLOCATED();
 public:
-    ScopedTexture2DRestorer(WebGLRenderingContextBase* context)
+    explicit ScopedTexture2DRestorer(WebGLRenderingContextBase* context)
         : m_context(context)
     {
     }
@@ -480,32 +486,60 @@ public:
     }
 
 private:
-    WebGLRenderingContextBase* m_context;
+    RawPtrWillBeMember<WebGLRenderingContextBase> m_context;
 };
 
-class WebGLRenderingContextLostCallback : public blink::WebGraphicsContext3D::WebGraphicsContextLostCallback {
-    WTF_MAKE_FAST_ALLOCATED;
+class WebGLRenderingContextLostCallback FINAL : public NoBaseWillBeGarbageCollectedFinalized<WebGLRenderingContextLostCallback>, public blink::WebGraphicsContext3D::WebGraphicsContextLostCallback {
+    WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
-    explicit WebGLRenderingContextLostCallback(WebGLRenderingContextBase* cb) : m_context(cb) { }
+    static PassOwnPtrWillBeRawPtr<WebGLRenderingContextLostCallback> create(WebGLRenderingContextBase* context)
+    {
+        return adoptPtrWillBeNoop(new WebGLRenderingContextLostCallback(context));
+    }
+
+    virtual ~WebGLRenderingContextLostCallback() { }
+
     virtual void onContextLost() { m_context->forceLostContext(WebGLRenderingContextBase::RealLostContext); }
-    virtual ~WebGLRenderingContextLostCallback() {}
+
+    void trace(Visitor* visitor)
+    {
+        visitor->trace(m_context);
+    }
+
 private:
-    WebGLRenderingContextBase* m_context;
+    explicit WebGLRenderingContextLostCallback(WebGLRenderingContextBase* context)
+        : m_context(context) { }
+
+    RawPtrWillBeMember<WebGLRenderingContextBase> m_context;
 };
 
-class WebGLRenderingContextErrorMessageCallback : public blink::WebGraphicsContext3D::WebGraphicsErrorMessageCallback {
-    WTF_MAKE_FAST_ALLOCATED;
+class WebGLRenderingContextErrorMessageCallback FINAL : public NoBaseWillBeGarbageCollectedFinalized<WebGLRenderingContextErrorMessageCallback>, public blink::WebGraphicsContext3D::WebGraphicsErrorMessageCallback {
+    WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
-    explicit WebGLRenderingContextErrorMessageCallback(WebGLRenderingContextBase* cb) : m_context(cb) { }
+    static PassOwnPtrWillBeRawPtr<WebGLRenderingContextErrorMessageCallback> create(WebGLRenderingContextBase* context)
+    {
+        return adoptPtrWillBeNoop(new WebGLRenderingContextErrorMessageCallback(context));
+    }
+
+    virtual ~WebGLRenderingContextErrorMessageCallback() { }
+
     virtual void onErrorMessage(const blink::WebString& message, blink::WGC3Dint)
     {
         if (m_context->m_synthesizedErrorsToConsole)
             m_context->printGLErrorToConsole(message);
         InspectorInstrumentation::didFireWebGLErrorOrWarning(m_context->canvas(), message);
     }
-    virtual ~WebGLRenderingContextErrorMessageCallback() { }
+
+    void trace(Visitor* visitor)
+    {
+        visitor->trace(m_context);
+    }
+
 private:
-    WebGLRenderingContextBase* m_context;
+    explicit WebGLRenderingContextErrorMessageCallback(WebGLRenderingContextBase* context)
+        : m_context(context) { }
+
+    RawPtrWillBeMember<WebGLRenderingContextBase> m_context;
 };
 
 WebGLRenderingContextBase::WebGLRenderingContextBase(HTMLCanvasElement* passedCanvas, PassOwnPtr<blink::WebGraphicsContext3D> context, WebGLContextAttributes* requestedAttributes)
@@ -539,6 +573,10 @@ WebGLRenderingContextBase::WebGLRenderingContextBase(HTMLCanvasElement* passedCa
     if (!m_drawingBuffer)
         return;
 
+#if ENABLE(OILPAN)
+    m_sharedWebGraphicsContext3D = WebGLSharedWebGraphicsContext3D::create(m_drawingBuffer);
+#endif
+
     m_drawingBuffer->bind();
     setupFlags();
     initializeNewContext();
@@ -625,8 +663,8 @@ void WebGLRenderingContextBase::initializeNewContext()
     webContext()->viewport(0, 0, drawingBufferWidth(), drawingBufferHeight());
     webContext()->scissor(0, 0, drawingBufferWidth(), drawingBufferHeight());
 
-    m_contextLostCallbackAdapter = adoptPtr(new WebGLRenderingContextLostCallback(this));
-    m_errorMessageCallbackAdapter = adoptPtr(new WebGLRenderingContextErrorMessageCallback(this));
+    m_contextLostCallbackAdapter = WebGLRenderingContextLostCallback::create(this);
+    m_errorMessageCallbackAdapter = WebGLRenderingContextErrorMessageCallback::create(this);
 
     webContext()->setContextLostCallback(m_contextLostCallbackAdapter.get());
     webContext()->setErrorMessageCallback(m_errorMessageCallbackAdapter.get());
@@ -678,6 +716,7 @@ unsigned WebGLRenderingContextBase::getWebGLVersion(const CanvasRenderingContext
 
 WebGLRenderingContextBase::~WebGLRenderingContextBase()
 {
+#if !ENABLE(OILPAN)
     // Remove all references to WebGLObjects so if they are the last reference
     // they will be freed before the last context is removed from the context group.
     m_boundArrayBuffer = nullptr;
@@ -689,8 +728,8 @@ WebGLRenderingContextBase::~WebGLRenderingContextBase()
     m_renderbufferBinding = nullptr;
 
     for (size_t i = 0; i < m_textureUnits.size(); ++i) {
-      m_textureUnits[i].m_texture2DBinding = nullptr;
-      m_textureUnits[i].m_textureCubeMapBinding = nullptr;
+        m_textureUnits[i].m_texture2DBinding = nullptr;
+        m_textureUnits[i].m_textureCubeMapBinding = nullptr;
     }
 
     m_blackTexture2D = nullptr;
@@ -698,9 +737,9 @@ WebGLRenderingContextBase::~WebGLRenderingContextBase()
 
     detachAndRemoveAllObjects();
 
-    // release all extensions
-    for (size_t i = 0; i < m_extensions.size(); ++i)
-        delete m_extensions[i];
+    // Release all extensions now.
+    m_extensions.clear();
+#endif
 
     // Context must be removed from the group prior to the destruction of the
     // WebGraphicsContext3D, otherwise shared objects may not be properly deleted.
@@ -709,11 +748,9 @@ WebGLRenderingContextBase::~WebGLRenderingContextBase()
     destroyContext();
 
 #if !ENABLE(OILPAN)
-    if (m_multisamplingObserverRegistered) {
-        Page* page = canvas()->document().page();
-        if (page)
+    if (m_multisamplingObserverRegistered)
+        if (Page* page = canvas()->document().page())
             page->removeMultisamplingChangedObserver(this);
-    }
 #endif
 
     willDestroyContext(this);
@@ -732,8 +769,18 @@ void WebGLRenderingContextBase::destroyContext()
     webContext()->setErrorMessageCallback(0);
 
     ASSERT(m_drawingBuffer);
+#if ENABLE(OILPAN)
+    // The DrawingBuffer ref pointers are cleared, but the
+    // WebGLSharedWebGraphicsContext3D object will hold onto the
+    // DrawingBuffer for as long as needed (== until all
+    // context objects have been finalized), at which point
+    // DrawingBuffer destruction happens.
+    m_drawingBuffer.clear();
+    m_sharedWebGraphicsContext3D.clear();
+#else
     m_drawingBuffer->beginDestruction();
     m_drawingBuffer.clear();
+#endif
 }
 
 void WebGLRenderingContextBase::markContextChanged(ContentChangeType changeType)
@@ -766,7 +813,7 @@ bool WebGLRenderingContextBase::clearIfComposited(GLbitfield mask)
         || m_requestedAttributes->preserveDrawingBuffer() || (mask && m_framebufferBinding))
         return false;
 
-    RefPtr<WebGLContextAttributes> contextAttributes = getContextAttributes();
+    RefPtrWillBeRawPtr<WebGLContextAttributes> contextAttributes = getContextAttributes();
 
     // Determine if it's possible to combine the clear the user asked for and this clear.
     bool combinedClear = mask && !m_scissorEnabled;
@@ -1493,49 +1540,49 @@ void WebGLRenderingContextBase::copyTexSubImage2D(GLenum target, GLint level, GL
     webContext()->copyTexSubImage2D(target, level, xoffset, yoffset, x, y, width, height);
 }
 
-PassRefPtr<WebGLBuffer> WebGLRenderingContextBase::createBuffer()
+PassRefPtrWillBeRawPtr<WebGLBuffer> WebGLRenderingContextBase::createBuffer()
 {
     if (isContextLost())
         return nullptr;
-    RefPtr<WebGLBuffer> o = WebGLBuffer::create(this);
+    RefPtrWillBeRawPtr<WebGLBuffer> o = WebGLBuffer::create(this);
     addSharedObject(o.get());
-    return o;
+    return o.release();
 }
 
-PassRefPtr<WebGLFramebuffer> WebGLRenderingContextBase::createFramebuffer()
+PassRefPtrWillBeRawPtr<WebGLFramebuffer> WebGLRenderingContextBase::createFramebuffer()
 {
     if (isContextLost())
         return nullptr;
-    RefPtr<WebGLFramebuffer> o = WebGLFramebuffer::create(this);
+    RefPtrWillBeRawPtr<WebGLFramebuffer> o = WebGLFramebuffer::create(this);
     addContextObject(o.get());
-    return o;
+    return o.release();
 }
 
-PassRefPtr<WebGLTexture> WebGLRenderingContextBase::createTexture()
+PassRefPtrWillBeRawPtr<WebGLTexture> WebGLRenderingContextBase::createTexture()
 {
     if (isContextLost())
         return nullptr;
-    RefPtr<WebGLTexture> o = WebGLTexture::create(this);
+    RefPtrWillBeRawPtr<WebGLTexture> o = WebGLTexture::create(this);
     addSharedObject(o.get());
-    return o;
+    return o.release();
 }
 
-PassRefPtr<WebGLProgram> WebGLRenderingContextBase::createProgram()
+PassRefPtrWillBeRawPtr<WebGLProgram> WebGLRenderingContextBase::createProgram()
 {
     if (isContextLost())
         return nullptr;
-    RefPtr<WebGLProgram> o = WebGLProgram::create(this);
+    RefPtrWillBeRawPtr<WebGLProgram> o = WebGLProgram::create(this);
     addSharedObject(o.get());
-    return o;
+    return o.release();
 }
 
-PassRefPtr<WebGLRenderbuffer> WebGLRenderingContextBase::createRenderbuffer()
+PassRefPtrWillBeRawPtr<WebGLRenderbuffer> WebGLRenderingContextBase::createRenderbuffer()
 {
     if (isContextLost())
         return nullptr;
-    RefPtr<WebGLRenderbuffer> o = WebGLRenderbuffer::create(this);
+    RefPtrWillBeRawPtr<WebGLRenderbuffer> o = WebGLRenderbuffer::create(this);
     addSharedObject(o.get());
-    return o;
+    return o.release();
 }
 
 WebGLRenderbuffer* WebGLRenderingContextBase::ensureEmulatedStencilBuffer(GLenum target, WebGLRenderbuffer* renderbuffer)
@@ -1550,7 +1597,7 @@ WebGLRenderbuffer* WebGLRenderingContextBase::ensureEmulatedStencilBuffer(GLenum
     return renderbuffer->emulatedStencilBuffer();
 }
 
-PassRefPtr<WebGLShader> WebGLRenderingContextBase::createShader(GLenum type)
+PassRefPtrWillBeRawPtr<WebGLShader> WebGLRenderingContextBase::createShader(GLenum type)
 {
     if (isContextLost())
         return nullptr;
@@ -1559,9 +1606,9 @@ PassRefPtr<WebGLShader> WebGLRenderingContextBase::createShader(GLenum type)
         return nullptr;
     }
 
-    RefPtr<WebGLShader> o = WebGLShader::create(this, type);
+    RefPtrWillBeRawPtr<WebGLShader> o = WebGLShader::create(this, type);
     addSharedObject(o.get());
-    return o;
+    return o.release();
 }
 
 void WebGLRenderingContextBase::cullFace(GLenum mode)
@@ -2007,7 +2054,7 @@ void WebGLRenderingContextBase::generateMipmap(GLenum target)
     tex->generateMipmapLevelInfo();
 }
 
-PassRefPtr<WebGLActiveInfo> WebGLRenderingContextBase::getActiveAttrib(WebGLProgram* program, GLuint index)
+PassRefPtrWillBeRawPtr<WebGLActiveInfo> WebGLRenderingContextBase::getActiveAttrib(WebGLProgram* program, GLuint index)
 {
     if (isContextLost() || !validateWebGLObject("getActiveAttrib", program))
         return nullptr;
@@ -2017,7 +2064,7 @@ PassRefPtr<WebGLActiveInfo> WebGLRenderingContextBase::getActiveAttrib(WebGLProg
     return WebGLActiveInfo::create(info.name, info.type, info.size);
 }
 
-PassRefPtr<WebGLActiveInfo> WebGLRenderingContextBase::getActiveUniform(WebGLProgram* program, GLuint index)
+PassRefPtrWillBeRawPtr<WebGLActiveInfo> WebGLRenderingContextBase::getActiveUniform(WebGLProgram* program, GLuint index)
 {
     if (isContextLost() || !validateWebGLObject("getActiveUniform", program))
         return nullptr;
@@ -2027,12 +2074,12 @@ PassRefPtr<WebGLActiveInfo> WebGLRenderingContextBase::getActiveUniform(WebGLPro
     return WebGLActiveInfo::create(info.name, info.type, info.size);
 }
 
-Nullable<Vector<RefPtr<WebGLShader> > > WebGLRenderingContextBase::getAttachedShaders(WebGLProgram* program)
+Nullable<WillBeHeapVector<RefPtrWillBeMember<WebGLShader> > > WebGLRenderingContextBase::getAttachedShaders(WebGLProgram* program)
 {
     if (isContextLost() || !validateWebGLObject("getAttachedShaders", program))
-        return Nullable<Vector<RefPtr<WebGLShader> > >();
+        return Nullable<WillBeHeapVector<RefPtrWillBeMember<WebGLShader> > >();
 
-    Vector<RefPtr<WebGLShader> > shaderObjects;
+    WillBeHeapVector<RefPtrWillBeMember<WebGLShader> > shaderObjects;
     const GLenum shaderType[] = {
         GL_VERTEX_SHADER,
         GL_FRAGMENT_SHADER
@@ -2083,14 +2130,14 @@ WebGLGetInfo WebGLRenderingContextBase::getBufferParameter(GLenum target, GLenum
     return WebGLGetInfo(static_cast<unsigned>(value));
 }
 
-PassRefPtr<WebGLContextAttributes> WebGLRenderingContextBase::getContextAttributes()
+PassRefPtrWillBeRawPtr<WebGLContextAttributes> WebGLRenderingContextBase::getContextAttributes()
 {
     if (isContextLost())
         return nullptr;
     // We always need to return a new WebGLContextAttributes object to
     // prevent the user from mutating any cached version.
     blink::WebGraphicsContext3D::Attributes attrs = m_drawingBuffer->getActualAttributes();
-    RefPtr<WebGLContextAttributes> attributes = m_requestedAttributes->clone();
+    RefPtrWillBeRawPtr<WebGLContextAttributes> attributes = m_requestedAttributes->clone();
     // Some requested attributes may not be honored, so we need to query the underlying
     // context/drawing buffer and adjust accordingly.
     if (m_requestedAttributes->depth() && !attrs.depth)
@@ -2143,18 +2190,18 @@ bool WebGLRenderingContextBase::extensionSupportedAndAllowed(const ExtensionTrac
 }
 
 
-PassRefPtr<WebGLExtension> WebGLRenderingContextBase::getExtension(const String& name)
+PassRefPtrWillBeRawPtr<WebGLExtension> WebGLRenderingContextBase::getExtension(const String& name)
 {
     if (isContextLost())
         return nullptr;
 
     for (size_t i = 0; i < m_extensions.size(); ++i) {
-        ExtensionTracker* tracker = m_extensions[i];
+        ExtensionTracker* tracker = m_extensions[i].get();
         if (tracker->matchesNameWithPrefixes(name)) {
             if (!extensionSupportedAndAllowed(tracker))
                 return nullptr;
 
-            RefPtr<WebGLExtension> extension = tracker->getExtension(this);
+            RefPtrWillBeRawPtr<WebGLExtension> extension = tracker->getExtension(this);
             if (extension)
                 m_extensionEnabled[extension->name()] = true;
             return extension.release();
@@ -2190,7 +2237,7 @@ WebGLGetInfo WebGLRenderingContextBase::getFramebufferAttachmentParameter(GLenum
         case GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE:
             return WebGLGetInfo(GL_TEXTURE);
         case GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME:
-            return WebGLGetInfo(PassRefPtr<WebGLTexture>(static_cast<WebGLTexture*>(object)));
+            return WebGLGetInfo(PassRefPtrWillBeRawPtr<WebGLTexture>(static_cast<WebGLTexture*>(object)));
         case GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL:
         case GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_CUBE_MAP_FACE:
             {
@@ -2207,7 +2254,7 @@ WebGLGetInfo WebGLRenderingContextBase::getFramebufferAttachmentParameter(GLenum
         case GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE:
             return WebGLGetInfo(GL_RENDERBUFFER);
         case GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME:
-            return WebGLGetInfo(PassRefPtr<WebGLRenderbuffer>(static_cast<WebGLRenderbuffer*>(object)));
+            return WebGLGetInfo(PassRefPtrWillBeRawPtr<WebGLRenderbuffer>(static_cast<WebGLRenderbuffer*>(object)));
         default:
             synthesizeGLError(GL_INVALID_ENUM, "getFramebufferAttachmentParameter", "invalid parameter name for renderbuffer attachment");
             return WebGLGetInfo();
@@ -2230,7 +2277,7 @@ WebGLGetInfo WebGLRenderingContextBase::getParameter(GLenum pname)
     case GL_ALPHA_BITS:
         return getIntParameter(pname);
     case GL_ARRAY_BUFFER_BINDING:
-        return WebGLGetInfo(PassRefPtr<WebGLBuffer>(m_boundArrayBuffer));
+        return WebGLGetInfo(PassRefPtrWillBeRawPtr<WebGLBuffer>(m_boundArrayBuffer.get()));
     case GL_BLEND:
         return getBooleanParameter(pname);
     case GL_BLEND_COLOR:
@@ -2260,7 +2307,7 @@ WebGLGetInfo WebGLRenderingContextBase::getParameter(GLenum pname)
     case GL_CULL_FACE_MODE:
         return getUnsignedIntParameter(pname);
     case GL_CURRENT_PROGRAM:
-        return WebGLGetInfo(PassRefPtr<WebGLProgram>(m_currentProgram));
+        return WebGLGetInfo(PassRefPtrWillBeRawPtr<WebGLProgram>(m_currentProgram.get()));
     case GL_DEPTH_BITS:
         if (!m_framebufferBinding && !m_requestedAttributes->depth())
             return WebGLGetInfo(intZero);
@@ -2278,9 +2325,9 @@ WebGLGetInfo WebGLRenderingContextBase::getParameter(GLenum pname)
     case GL_DITHER:
         return getBooleanParameter(pname);
     case GL_ELEMENT_ARRAY_BUFFER_BINDING:
-        return WebGLGetInfo(PassRefPtr<WebGLBuffer>(m_boundVertexArrayObject->boundElementArrayBuffer()));
+        return WebGLGetInfo(PassRefPtrWillBeRawPtr<WebGLBuffer>(m_boundVertexArrayObject->boundElementArrayBuffer()));
     case GL_FRAMEBUFFER_BINDING:
-        return WebGLGetInfo(PassRefPtr<WebGLFramebuffer>(m_framebufferBinding));
+        return WebGLGetInfo(PassRefPtrWillBeRawPtr<WebGLFramebuffer>(m_framebufferBinding.get()));
     case GL_FRONT_FACE:
         return getUnsignedIntParameter(pname);
     case GL_GENERATE_MIPMAP_HINT:
@@ -2329,7 +2376,7 @@ WebGLGetInfo WebGLRenderingContextBase::getParameter(GLenum pname)
     case GL_RED_BITS:
         return getIntParameter(pname);
     case GL_RENDERBUFFER_BINDING:
-        return WebGLGetInfo(PassRefPtr<WebGLRenderbuffer>(m_renderbufferBinding));
+        return WebGLGetInfo(PassRefPtrWillBeRawPtr<WebGLRenderbuffer>(m_renderbufferBinding.get()));
     case GL_RENDERER:
         return WebGLGetInfo(String("WebKit WebGL"));
     case GL_SAMPLE_BUFFERS:
@@ -2385,9 +2432,9 @@ WebGLGetInfo WebGLRenderingContextBase::getParameter(GLenum pname)
     case GL_SUBPIXEL_BITS:
         return getIntParameter(pname);
     case GL_TEXTURE_BINDING_2D:
-        return WebGLGetInfo(PassRefPtr<WebGLTexture>(m_textureUnits[m_activeTextureUnit].m_texture2DBinding));
+        return WebGLGetInfo(PassRefPtrWillBeRawPtr<WebGLTexture>(m_textureUnits[m_activeTextureUnit].m_texture2DBinding.get()));
     case GL_TEXTURE_BINDING_CUBE_MAP:
-        return WebGLGetInfo(PassRefPtr<WebGLTexture>(m_textureUnits[m_activeTextureUnit].m_textureCubeMapBinding));
+        return WebGLGetInfo(PassRefPtrWillBeRawPtr<WebGLTexture>(m_textureUnits[m_activeTextureUnit].m_textureCubeMapBinding.get()));
     case GL_UNPACK_ALIGNMENT:
         return getIntParameter(pname);
     case GC3D_UNPACK_FLIP_Y_WEBGL:
@@ -2420,7 +2467,7 @@ WebGLGetInfo WebGLRenderingContextBase::getParameter(GLenum pname)
     case GL_VERTEX_ARRAY_BINDING_OES: // OES_vertex_array_object
         if (extensionEnabled(OESVertexArrayObjectName)) {
             if (!m_boundVertexArrayObject->isDefaultObject())
-                return WebGLGetInfo(PassRefPtr<WebGLVertexArrayObjectOES>(m_boundVertexArrayObject));
+                return WebGLGetInfo(PassRefPtrWillBeRawPtr<WebGLVertexArrayObjectOES>(m_boundVertexArrayObject.get()));
             return WebGLGetInfo();
         }
         synthesizeGLError(GL_INVALID_ENUM, "getParameter", "invalid parameter name, OES_vertex_array_object not enabled");
@@ -2560,7 +2607,7 @@ String WebGLRenderingContextBase::getShaderInfoLog(WebGLShader* shader)
     return ensureNotNull(webContext()->getShaderInfoLog(objectOrZero(shader)));
 }
 
-PassRefPtr<WebGLShaderPrecisionFormat> WebGLRenderingContextBase::getShaderPrecisionFormat(GLenum shaderType, GLenum precisionType)
+PassRefPtrWillBeRawPtr<WebGLShaderPrecisionFormat> WebGLRenderingContextBase::getShaderPrecisionFormat(GLenum shaderType, GLenum precisionType)
 {
     if (isContextLost())
         return nullptr;
@@ -2608,7 +2655,7 @@ Nullable<Vector<String> > WebGLRenderingContextBase::getSupportedExtensions()
     Vector<String> result;
 
     for (size_t i = 0; i < m_extensions.size(); ++i) {
-        ExtensionTracker* tracker = m_extensions[i];
+        ExtensionTracker* tracker = m_extensions[i].get();
         if (extensionSupportedAndAllowed(tracker)) {
             const char* const* prefixes = tracker->prefixes();
             for (; *prefixes; ++prefixes) {
@@ -2797,7 +2844,7 @@ WebGLGetInfo WebGLRenderingContextBase::getUniform(WebGLProgram* program, const
     return WebGLGetInfo();
 }
 
-PassRefPtr<WebGLUniformLocation> WebGLRenderingContextBase::getUniformLocation(WebGLProgram* program, const String& name)
+PassRefPtrWillBeRawPtr<WebGLUniformLocation> WebGLRenderingContextBase::getUniformLocation(WebGLProgram* program, const String& name)
 {
     if (isContextLost() || !validateWebGLObject("getUniformLocation", program))
         return nullptr;
@@ -2834,7 +2881,7 @@ WebGLGetInfo WebGLRenderingContextBase::getVertexAttrib(GLuint index, GLenum pna
     case GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING:
         if (!state.bufferBinding || !state.bufferBinding->object())
             return WebGLGetInfo();
-        return WebGLGetInfo(PassRefPtr<WebGLBuffer>(state.bufferBinding));
+        return WebGLGetInfo(PassRefPtrWillBeRawPtr<WebGLBuffer>(state.bufferBinding.get()));
     case GL_VERTEX_ATTRIB_ARRAY_ENABLED:
         return WebGLGetInfo(state.enabled);
     case GL_VERTEX_ATTRIB_ARRAY_NORMALIZED:
@@ -4211,7 +4258,7 @@ void WebGLRenderingContextBase::loseContextImpl(WebGLRenderingContextBase::LostC
 
     // Lose all the extensions.
     for (size_t i = 0; i < m_extensions.size(); ++i) {
-        ExtensionTracker* tracker = m_extensions[i];
+        ExtensionTracker* tracker = m_extensions[i].get();
         tracker->loseExtension();
     }
 
@@ -4290,7 +4337,7 @@ void WebGLRenderingContextBase::addContextObject(WebGLContextObject* object)
 void WebGLRenderingContextBase::detachAndRemoveAllObjects()
 {
     while (m_contextObjects.size() > 0) {
-        HashSet<WebGLContextObject*>::iterator it = m_contextObjects.begin();
+        WillBeHeapHashSet<RawPtrWillBeWeakMember<WebGLContextObject> >::iterator it = m_contextObjects.begin();
         (*it)->detachContext();
     }
 }
@@ -5474,6 +5521,10 @@ void WebGLRenderingContextBase::maybeRestoreContext(Timer<WebGLRenderingContextB
 
     // If the context was lost due to RealLostContext, we need to destroy the old DrawingBuffer before creating new DrawingBuffer to ensure resource budget enough.
     if (m_drawingBuffer) {
+#if ENABLE(OILPAN)
+        if (m_sharedWebGraphicsContext3D)
+            m_sharedWebGraphicsContext3D->reset();
+#endif
         m_drawingBuffer->beginDestruction();
         m_drawingBuffer.clear();
     }
@@ -5498,6 +5549,13 @@ void WebGLRenderingContextBase::maybeRestoreContext(Timer<WebGLRenderingContextB
     }
 
     m_drawingBuffer = drawingBuffer.release();
+#if ENABLE(OILPAN)
+    if (m_sharedWebGraphicsContext3D)
+        m_sharedWebGraphicsContext3D->update(m_drawingBuffer);
+    else
+        m_sharedWebGraphicsContext3D = WebGLSharedWebGraphicsContext3D::create(m_drawingBuffer);
+#endif
+
     m_drawingBuffer->bind();
     m_lostContextErrors.clear();
     m_contextLost = false;
@@ -5607,7 +5665,7 @@ void WebGLRenderingContextBase::applyStencilTest()
     if (m_framebufferBinding)
         haveStencilBuffer = m_framebufferBinding->hasStencilBuffer();
     else {
-        RefPtr<WebGLContextAttributes> attributes = getContextAttributes();
+        RefPtrWillBeRawPtr<WebGLContextAttributes> attributes = getContextAttributes();
         haveStencilBuffer = attributes->stencil();
     }
     enableOrDisable(GL_STENCIL_TEST,
@@ -5701,4 +5759,62 @@ void WebGLRenderingContextBase::findNewMaxNonDefaultTextureUnit()
     m_onePlusMaxNonDefaultTextureUnit = 0;
 }
 
+void WebGLRenderingContextBase::TextureUnitState::trace(Visitor* visitor)
+{
+    visitor->trace(m_texture2DBinding);
+    visitor->trace(m_textureCubeMapBinding);
+}
+
+void WebGLRenderingContextBase::trace(Visitor* visitor)
+{
+    visitor->trace(m_contextObjects);
+    visitor->trace(m_contextLostCallbackAdapter);
+    visitor->trace(m_errorMessageCallbackAdapter);
+    visitor->trace(m_boundArrayBuffer);
+    visitor->trace(m_defaultVertexArrayObject);
+    visitor->trace(m_boundVertexArrayObject);
+    visitor->trace(m_vertexAttrib0Buffer);
+    visitor->trace(m_currentProgram);
+    visitor->trace(m_framebufferBinding);
+    visitor->trace(m_renderbufferBinding);
+    visitor->trace(m_textureUnits);
+    visitor->trace(m_blackTexture2D);
+    visitor->trace(m_blackTextureCubeMap);
+    visitor->trace(m_requestedAttributes);
+    visitor->trace(m_extensions);
+    CanvasRenderingContext::trace(visitor);
+}
+
+
+#if ENABLE(OILPAN)
+PassRefPtr<WebGLSharedWebGraphicsContext3D> WebGLSharedWebGraphicsContext3D::create(PassRefPtr<DrawingBuffer> buffer)
+{
+    return adoptRef(new WebGLSharedWebGraphicsContext3D(buffer));
+}
+
+WebGLSharedWebGraphicsContext3D::WebGLSharedWebGraphicsContext3D(PassRefPtr<DrawingBuffer> buffer)
+    : m_buffer(buffer)
+{
+}
+
+WebGLSharedWebGraphicsContext3D::~WebGLSharedWebGraphicsContext3D()
+{
+    if (m_buffer) {
+        m_buffer->beginDestruction();
+        m_buffer.clear();
+    }
+}
+
+void WebGLSharedWebGraphicsContext3D::reset()
+{
+    // Cleared without finalizing.
+    m_buffer.clear();
+}
+
+void WebGLSharedWebGraphicsContext3D::update(PassRefPtr<DrawingBuffer> buffer)
+{
+    m_buffer = buffer;
+}
+#endif
+
 } // namespace WebCore