Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1435 insertions, 0 deletions

diff --git a/dom/canvas/WebGLContext.h b/dom/canvas/WebGLContext.h
new file mode 100644
index 0000000000..12727c4969
--- /dev/null
+++ b/dom/canvas/WebGLContext.h
@@ -0,0 +1,1435 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef WEBGLCONTEXT_H_
+#define WEBGLCONTEXT_H_
+
+#include <bitset>
+#include <memory>
+#include <stdarg.h>
+
+#include "GLContextTypes.h"
+#include "GLDefs.h"
+#include "GLScreenBuffer.h"
+#include "js/ScalarType.h"  // js::Scalar::Type
+#include "mozilla/Attributes.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/CheckedInt.h"
+#include "mozilla/dom/ipc/IdType.h"
+#include "mozilla/dom/BindingDeclarations.h"
+#include "mozilla/dom/HTMLCanvasElement.h"
+#include "mozilla/dom/Nullable.h"
+#include "mozilla/dom/TypedArray.h"
+#include "mozilla/EnumeratedArray.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/StaticMutex.h"
+#include "mozilla/StaticPrefs_webgl.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/WeakPtr.h"
+#include "nsICanvasRenderingContextInternal.h"
+#include "nsTArray.h"
+#include "SurfaceTypes.h"
+#include "ScopedGLHelpers.h"
+#include "TexUnpackBlob.h"
+
+// Local
+#include "CacheInvalidator.h"
+#include "WebGLContextLossHandler.h"
+#include "WebGLExtensions.h"
+#include "WebGLObjectModel.h"
+#include "WebGLStrongTypes.h"
+#include "WebGLTypes.h"
+
+// Generated
+#include "mozilla/dom/WebGLRenderingContextBinding.h"
+#include "mozilla/dom/WebGL2RenderingContextBinding.h"
+
+#include <list>
+
+class nsIDocShell;
+
+// WebGL-only GLenums
+// clang-format off
+#define LOCAL_GL_BROWSER_DEFAULT_WEBGL              0x9244
+#define LOCAL_GL_CONTEXT_LOST_WEBGL                 0x9242
+#define LOCAL_GL_MAX_CLIENT_WAIT_TIMEOUT_WEBGL      0x9247
+#define LOCAL_GL_UNPACK_COLORSPACE_CONVERSION_WEBGL 0x9243
+#define LOCAL_GL_UNPACK_FLIP_Y_WEBGL                0x9240
+#define LOCAL_GL_UNPACK_PREMULTIPLY_ALPHA_WEBGL     0x9241
+// clang-format on
+
+namespace mozilla {
+class HostWebGLContext;
+class ScopedCopyTexImageSource;
+class ScopedDrawCallWrapper;
+class ScopedResolveTexturesForDraw;
+class WebGLBuffer;
+class WebGLExtensionBase;
+class WebGLFramebuffer;
+class WebGLProgram;
+class WebGLQuery;
+class WebGLRenderbuffer;
+class WebGLSampler;
+class WebGLShader;
+class WebGLSync;
+class WebGLTexture;
+class WebGLTransformFeedback;
+class WebGLVertexArray;
+
+namespace dom {
+class Document;
+class Element;
+class ImageData;
+class OwningHTMLCanvasElementOrOffscreenCanvas;
+struct WebGLContextAttributes;
+}  // namespace dom
+
+namespace gfx {
+class SourceSurface;
+class VRLayerChild;
+}  // namespace gfx
+
+namespace gl {
+class GLScreenBuffer;
+class MozFramebuffer;
+class SharedSurface;
+class Texture;
+}  // namespace gl
+
+namespace layers {
+class CompositableHost;
+class RemoteTextureOwnerClient;
+class SurfaceDescriptor;
+}  // namespace layers
+
+namespace webgl {
+class AvailabilityRunnable;
+struct CachedDrawFetchLimits;
+struct FbAttachInfo;
+struct FormatInfo;
+class FormatUsageAuthority;
+struct FormatUsageInfo;
+struct ImageInfo;
+struct LinkedProgramInfo;
+struct SamplerUniformInfo;
+struct SamplingState;
+class ScopedPrepForResourceClear;
+class ShaderValidator;
+class TexUnpackBlob;
+struct UniformInfo;
+struct UniformBlockInfo;
+struct VertAttribPointerDesc;
+}  // namespace webgl
+
+struct WebGLTexImageData {
+  TexImageTarget mTarget;
+  int32_t mRowLength;
+  uint32_t mWidth;
+  uint32_t mHeight;
+  uint32_t mDepth;
+  gfxAlphaType mSrcAlphaType;
+};
+
+struct WebGLTexPboOffset {
+  TexImageTarget mTarget;
+  uint32_t mWidth;
+  uint32_t mHeight;
+  uint32_t mDepth;
+  WebGLsizeiptr mPboOffset;
+  bool mHasExpectedImageSize;
+  GLsizei mExpectedImageSize;
+};
+
+WebGLTexelFormat GetWebGLTexelFormat(TexInternalFormat format);
+
+void AssertUintParamCorrect(gl::GLContext* gl, GLenum pname, GLuint shadow);
+
+// From WebGLContextUtils
+TexTarget TexImageTargetToTexTarget(TexImageTarget texImageTarget);
+
+struct WebGLIntOrFloat {
+  const enum { Int, Float, Uint } mType;
+
+  union {
+    GLint i;
+    GLfloat f;
+    GLuint u;
+  } mValue;
+
+  explicit WebGLIntOrFloat(GLint i) : mType(Int) { mValue.i = i; }
+  explicit WebGLIntOrFloat(GLfloat f) : mType(Float) { mValue.f = f; }
+
+  GLint AsInt() const {
+    return (mType == Int) ? mValue.i : NS_lroundf(mValue.f);
+  }
+  GLfloat AsFloat() const {
+    return (mType == Float) ? mValue.f : GLfloat(mValue.i);
+  }
+};
+
+////////////////////////////////////
+
+namespace webgl {
+
+class AvailabilityRunnable final : public DiscardableRunnable {
+ public:
+  const WeakPtr<const ClientWebGLContext> mWebGL;
+  std::vector<WeakPtr<WebGLQueryJS>> mQueries;
+  std::vector<WeakPtr<WebGLSyncJS>> mSyncs;
+
+  explicit AvailabilityRunnable(const ClientWebGLContext* webgl);
+  ~AvailabilityRunnable();
+
+  NS_IMETHOD Run() override;
+};
+
+}  // namespace webgl
+
+////////////////////////////////////////////////////////////////////////////////
+
+class WebGLContext : public VRefCounted, public SupportsWeakPtr {
+  friend class ScopedDrawCallWrapper;
+  friend class ScopedDrawWithTransformFeedback;
+  friend class ScopedFakeVertexAttrib0;
+  friend class ScopedFBRebinder;
+  friend class WebGL2Context;
+  friend class WebGLContextUserData;
+  friend class WebGLExtensionCompressedTextureASTC;
+  friend class WebGLExtensionCompressedTextureBPTC;
+  friend class WebGLExtensionCompressedTextureES3;
+  friend class WebGLExtensionCompressedTextureETC1;
+  friend class WebGLExtensionCompressedTexturePVRTC;
+  friend class WebGLExtensionCompressedTextureRGTC;
+  friend class WebGLExtensionCompressedTextureS3TC;
+  friend class WebGLExtensionCompressedTextureS3TC_SRGB;
+  friend class WebGLExtensionDepthTexture;
+  friend class WebGLExtensionDisjointTimerQuery;
+  friend class WebGLExtensionDrawBuffers;
+  friend class WebGLExtensionLoseContext;
+  friend class WebGLExtensionMOZDebug;
+  friend class WebGLExtensionVertexArray;
+  friend class WebGLMemoryTracker;
+  friend class webgl::AvailabilityRunnable;
+  friend struct webgl::LinkedProgramInfo;
+  friend struct webgl::SamplerUniformInfo;
+  friend class webgl::ScopedPrepForResourceClear;
+  friend struct webgl::UniformBlockInfo;
+
+  friend const webgl::CachedDrawFetchLimits* ValidateDraw(WebGLContext*, GLenum,
+                                                          uint32_t);
+  friend RefPtr<const webgl::LinkedProgramInfo> QueryProgramInfo(
+      WebGLProgram* prog, gl::GLContext* gl);
+
+  MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(WebGLContext, override)
+
+  enum {
+    UNPACK_FLIP_Y_WEBGL = 0x9240,
+    UNPACK_PREMULTIPLY_ALPHA_WEBGL = 0x9241,
+    // We throw InvalidOperation in TexImage if we fail to use GPU fast-path
+    // for texture copy when it is set to true, only for debug purpose.
+    UNPACK_REQUIRE_FASTPATH = 0x10001,
+    CONTEXT_LOST_WEBGL = 0x9242,
+    UNPACK_COLORSPACE_CONVERSION_WEBGL = 0x9243,
+    BROWSER_DEFAULT_WEBGL = 0x9244,
+    UNMASKED_VENDOR_WEBGL = 0x9245,
+    UNMASKED_RENDERER_WEBGL = 0x9246
+  };
+
+ private:
+  class LruPosition final {
+    std::list<WebGLContext*>::iterator mItr;
+
+    LruPosition(const LruPosition&) = delete;
+    LruPosition(LruPosition&&) = delete;
+    LruPosition& operator=(const LruPosition&) = delete;
+    LruPosition& operator=(LruPosition&&) = delete;
+
+   public:
+    void AssignLocked(WebGLContext& aContext) MOZ_REQUIRES(sLruMutex);
+    void Reset();
+    void ResetLocked() MOZ_REQUIRES(sLruMutex);
+    bool IsInsertedLocked() const MOZ_REQUIRES(sLruMutex);
+
+    LruPosition();
+    explicit LruPosition(WebGLContext&);
+
+    ~LruPosition() { Reset(); }
+  };
+
+  mutable LruPosition mLruPosition MOZ_GUARDED_BY(sLruMutex);
+
+  void BumpLruLocked() MOZ_REQUIRES(sLruMutex);
+
+ public:
+  void BumpLru();
+  void LoseLruContextIfLimitExceeded();
+
+  // -
+
+  // We've had issues in the past with nulling `gl` without actually releasing
+  // all of our resources. This construction ensures that we are aware that we
+  // should only null `gl` in DestroyResourcesAndContext.
+  RefPtr<gl::GLContext> mGL_OnlyClearInDestroyResourcesAndContext;
+
+ public:
+  // Grab a const reference so we can see changes, but can't make changes.
+  const decltype(mGL_OnlyClearInDestroyResourcesAndContext)& gl;
+
+ public:
+  void CheckForInactivity();
+
+ protected:
+  const WeakPtr<HostWebGLContext> mHost;
+  const bool mResistFingerprinting;
+  WebGLContextOptions mOptions;
+  const uint32_t mPrincipalKey;
+  Maybe<webgl::Limits> mLimits;
+  const uint32_t mMaxVertIdsPerDraw =
+      StaticPrefs::webgl_max_vert_ids_per_draw();
+
+  bool mIsContextLost = false;
+  Atomic<bool> mPendingContextLoss = Atomic<bool>{false};
+  webgl::ContextLossReason mPendingContextLossReason =
+      webgl::ContextLossReason::None;
+  const uint32_t mMaxPerfWarnings = StaticPrefs::webgl_perf_max_warnings();
+  mutable uint64_t mNumPerfWarnings = 0;
+  const uint32_t mMaxAcceptableFBStatusInvals =
+      StaticPrefs::webgl_perf_max_acceptable_fb_status_invals();
+  bool mWarnOnce_DepthTexCompareFilterable = true;
+
+  uint64_t mNextFenceId = 1;
+  uint64_t mCompletedFenceId = 0;
+
+  std::unique_ptr<gl::Texture> mIncompleteTexOverride;
+
+ public:
+  class FuncScope;
+
+ private:
+  mutable FuncScope* mFuncScope = nullptr;
+
+ public:
+  static RefPtr<WebGLContext> Create(HostWebGLContext*,
+                                     const webgl::InitContextDesc&,
+                                     webgl::InitContextResult* out);
+
+ private:
+  bool mIsRgb8Renderable = false;
+  void FinishInit();
+
+ protected:
+  WebGLContext(HostWebGLContext*, const webgl::InitContextDesc&);
+  virtual ~WebGLContext();
+
+  RefPtr<layers::CompositableHost> mCompositableHost;
+
+  layers::LayersBackend mBackend = layers::LayersBackend::LAYERS_NONE;
+
+ public:
+  void Resize(uvec2 size);
+
+  void SetCompositableHost(RefPtr<layers::CompositableHost>& aCompositableHost);
+
+  /**
+   * An abstract base class to be implemented by callers wanting to be notified
+   * that a refresh has occurred. Callers must ensure an observer is removed
+   * before it is destroyed.
+   */
+  virtual void DidRefresh();
+
+  void OnMemoryPressure();
+
+  // -
+
+  /*
+
+  Here are the bind calls that are supposed to be fully-validated client side,
+  so that client's binding state doesn't diverge:
+  * AttachShader
+  * DetachShader
+  * BindFramebuffer
+  * FramebufferAttach
+  * BindBuffer
+  * BindBufferRange
+  * BindTexture
+  * UseProgram
+  * BindSampler
+  * BindTransformFeedback
+  * BindVertexArray
+  * BeginQuery
+  * EndQuery
+  * ActiveTexture
+
+  */
+
+  const auto& CurFuncScope() const { return *mFuncScope; }
+  const char* FuncName() const;
+
+  class FuncScope final {
+   public:
+    const WebGLContext& mWebGL;
+    const char* const mFuncName;
+    bool mBindFailureGuard = false;
+
+   public:
+    FuncScope(const WebGLContext& webgl, const char* funcName);
+    ~FuncScope();
+  };
+
+  void GenerateErrorImpl(const GLenum err, const nsACString& text) const {
+    GenerateErrorImpl(err, std::string(text.BeginReading()));
+  }
+  void GenerateErrorImpl(const GLenum err, const std::string& text) const;
+
+  void GenerateError(const webgl::ErrorInfo& err) {
+    GenerateError(err.type, "%s", err.info.c_str());
+  }
+
+  template <typename... Args>
+  void GenerateError(const GLenum err, const char* const fmt,
+                     const Args&... args) const {
+    MOZ_ASSERT(FuncName());
+
+    nsCString text;
+    text.AppendPrintf("WebGL warning: %s: ", FuncName());
+
+#ifdef __clang__
+#  pragma clang diagnostic push
+#  pragma clang diagnostic ignored "-Wformat-security"
+#elif defined(__GNUC__)
+#  pragma GCC diagnostic push
+#  pragma GCC diagnostic ignored "-Wformat-security"
+#endif
+    text.AppendPrintf(fmt, args...);
+#ifdef __clang__
+#  pragma clang diagnostic pop
+#elif defined(__GNUC__)
+#  pragma GCC diagnostic pop
+#endif
+
+    GenerateErrorImpl(err, text);
+  }
+
+  template <typename... Args>
+  void ErrorInvalidEnum(const char* const fmt, const Args&... args) const {
+    GenerateError(LOCAL_GL_INVALID_ENUM, fmt, args...);
+  }
+  template <typename... Args>
+  void ErrorInvalidOperation(const char* const fmt, const Args&... args) const {
+    GenerateError(LOCAL_GL_INVALID_OPERATION, fmt, args...);
+  }
+  template <typename... Args>
+  void ErrorInvalidValue(const char* const fmt, const Args&... args) const {
+    GenerateError(LOCAL_GL_INVALID_VALUE, fmt, args...);
+  }
+  template <typename... Args>
+  void ErrorInvalidFramebufferOperation(const char* const fmt,
+                                        const Args&... args) const {
+    GenerateError(LOCAL_GL_INVALID_FRAMEBUFFER_OPERATION, fmt, args...);
+  }
+  template <typename... Args>
+  void ErrorOutOfMemory(const char* const fmt, const Args&... args) const {
+    GenerateError(LOCAL_GL_OUT_OF_MEMORY, fmt, args...);
+  }
+
+  template <typename... Args>
+  void ErrorImplementationBug(const char* const fmt,
+                              const Args&... args) const {
+    const nsPrintfCString newFmt(
+        "Implementation bug, please file at %s! %s",
+        "https://bugzilla.mozilla.org/"
+        "enter_bug.cgi?product=Core&component=Canvas%3A+WebGL",
+        fmt);
+    GenerateError(LOCAL_GL_OUT_OF_MEMORY, newFmt.BeginReading(), args...);
+    MOZ_ASSERT(false, "WebGLContext::ErrorImplementationBug");
+    NS_ERROR("WebGLContext::ErrorImplementationBug");
+  }
+
+  void ErrorInvalidEnumInfo(const char* info, GLenum enumValue) const;
+  void ErrorInvalidEnumArg(const char* argName, GLenum val) const;
+
+  static const char* ErrorName(GLenum error);
+
+  void JsWarning(const std::string& text) const;
+
+  /**
+   * Return displayable name for GLenum.
+   * This version is like gl::GLenumToStr but with out the GL_ prefix to
+   * keep consistency with how errors are reported from WebGL.
+   * Returns hex formatted version of glenum if glenum is unknown.
+   */
+  static void EnumName(GLenum val, nsCString* out_name);
+
+  void DummyReadFramebufferOperation();
+
+  dom::ContentParentId GetContentId() const;
+
+  WebGLTexture* GetActiveTex(const GLenum texTarget) const;
+
+  gl::GLContext* GL() const { return gl; }
+
+  bool IsPremultAlpha() const { return mOptions.premultipliedAlpha; }
+
+  bool IsPreservingDrawingBuffer() const {
+    return mOptions.preserveDrawingBuffer;
+  }
+
+  // Present to compositor
+ private:
+  bool PresentInto(gl::SwapChain& swapChain);
+  bool PresentIntoXR(gl::SwapChain& swapChain, const gl::MozFramebuffer& xrFb);
+
+ public:
+  // Present swaps the front and back buffers of the swap chain for compositing.
+  // This assumes the framebuffer may directly alias with the back buffer,
+  // dependent on remoting state or other concerns. Framebuffer and swap chain
+  // surface formats are assumed to be similar to enable this aliasing. As such,
+  // the back buffer may be invalidated by this swap with the front buffer,
+  // unless overriden by explicitly setting the preserveDrawingBuffer option,
+  // which may incur a further copy to preserve the back buffer.
+  void Present(
+      WebGLFramebuffer*, layers::TextureType, const bool webvr,
+      const webgl::SwapChainOptions& options = webgl::SwapChainOptions());
+  // CopyToSwapChain forces a copy from the supplied framebuffer into the back
+  // buffer before swapping the front and back buffers of the swap chain for
+  // compositing. The formats of the framebuffer and the swap chain buffers
+  // may differ subject to available format conversion options. Since this
+  // operation uses an explicit copy, it inherently preserves the framebuffer
+  // without need to set the preserveDrawingBuffer option.
+  bool CopyToSwapChain(
+      WebGLFramebuffer*, layers::TextureType,
+      const webgl::SwapChainOptions& options = webgl::SwapChainOptions(),
+      layers::RemoteTextureOwnerClient* ownerClient = nullptr);
+  // In use cases where a framebuffer is used as an offscreen framebuffer and
+  // does not need to be committed to the swap chain, it may still be useful
+  // for the implementation to delineate distinct frames, such as when sharing
+  // a single WebGLContext amongst many distinct users. EndOfFrame signals that
+  // frame rendering is complete so that any implementation side-effects such
+  // as resetting internal profile counters or resource queues may be handled
+  // appropriately.
+  void EndOfFrame();
+  RefPtr<gfx::DataSourceSurface> GetFrontBufferSnapshot();
+  Maybe<uvec2> FrontBufferSnapshotInto(
+      const Maybe<Range<uint8_t>> dest,
+      const Maybe<size_t> destStride = Nothing());
+  Maybe<uvec2> FrontBufferSnapshotInto(
+      const std::shared_ptr<gl::SharedSurface>& front,
+      const Maybe<Range<uint8_t>> dest,
+      const Maybe<size_t> destStride = Nothing());
+  Maybe<uvec2> SnapshotInto(GLuint srcFb, const gfx::IntSize& size,
+                            const Range<uint8_t>& dest,
+                            const Maybe<size_t> destStride = Nothing());
+  gl::SwapChain* GetSwapChain(WebGLFramebuffer*, const bool webvr);
+  Maybe<layers::SurfaceDescriptor> GetFrontBuffer(WebGLFramebuffer*,
+                                                  const bool webvr);
+
+  void ClearVRSwapChain();
+
+  void RunContextLossTimer();
+  void CheckForContextLoss();
+  void HandlePendingContextLoss();
+
+  bool TryToRestoreContext();
+
+  void AssertCachedBindings() const;
+  void AssertCachedGlobalState() const;
+
+  // WebIDL WebGLRenderingContext API
+  void Commit();
+
+  uvec2 DrawingBufferSize();
+
+ public:
+  void GetContextAttributes(dom::Nullable<dom::WebGLContextAttributes>& retval);
+
+  // This is the entrypoint. Don't test against it directly.
+  bool IsContextLost() const {
+    auto* self = const_cast<WebGLContext*>(this);
+    if (self->mPendingContextLoss.exchange(false)) {
+      self->HandlePendingContextLoss();
+    }
+    return mIsContextLost;
+  }
+
+  // -
+
+  RefPtr<WebGLBuffer> CreateBuffer();
+  RefPtr<WebGLFramebuffer> CreateFramebuffer();
+  RefPtr<WebGLFramebuffer> CreateOpaqueFramebuffer(
+      const webgl::OpaqueFramebufferOptions& options);
+  RefPtr<WebGLProgram> CreateProgram();
+  RefPtr<WebGLQuery> CreateQuery();
+  RefPtr<WebGLRenderbuffer> CreateRenderbuffer();
+  RefPtr<WebGLShader> CreateShader(GLenum type);
+  RefPtr<WebGLTexture> CreateTexture();
+  RefPtr<WebGLVertexArray> CreateVertexArray();
+
+  // -
+
+  void AttachShader(WebGLProgram& prog, WebGLShader& shader);
+  void BindAttribLocation(WebGLProgram& prog, GLuint location,
+                          const std::string& name) const;
+  void BindFramebuffer(GLenum target, WebGLFramebuffer* fb);
+  void BindRenderbuffer(GLenum target, WebGLRenderbuffer* fb);
+  void BindVertexArray(WebGLVertexArray* vao);
+  void BlendColor(GLclampf r, GLclampf g, GLclampf b, GLclampf a);
+  void BlendEquationSeparate(Maybe<GLuint> i, GLenum modeRGB, GLenum modeAlpha);
+  void BlendFuncSeparate(Maybe<GLuint> i, GLenum srcRGB, GLenum dstRGB,
+                         GLenum srcAlpha, GLenum dstAlpha);
+  GLenum CheckFramebufferStatus(GLenum target);
+  void Clear(GLbitfield mask);
+  void ClearColor(GLclampf r, GLclampf g, GLclampf b, GLclampf a);
+  void ClearDepth(GLclampf v);
+  void ClearStencil(GLint v);
+  void ColorMask(Maybe<GLuint> i, uint8_t mask);
+  void CompileShader(WebGLShader& shader);
+
+ private:
+  void CompileShaderANGLE(WebGLShader* shader);
+  void CompileShaderBypass(WebGLShader* shader, const nsCString& shaderSource);
+
+ public:
+  void CullFace(GLenum face);
+  void DepthFunc(GLenum func);
+  void DepthMask(WebGLboolean b);
+  void DepthRange(GLclampf zNear, GLclampf zFar);
+  void DetachShader(WebGLProgram& prog, const WebGLShader& shader);
+  void DrawBuffers(const std::vector<GLenum>& buffers);
+  void Flush();
+  void Finish();
+
+  void FramebufferAttach(GLenum target, GLenum attachSlot,
+                         GLenum bindImageTarget,
+                         const webgl::FbAttachInfo& toAttach);
+
+  void FrontFace(GLenum mode);
+
+  Maybe<double> GetBufferParameter(GLenum target, GLenum pname);
+  webgl::CompileResult GetCompileResult(const WebGLShader&) const;
+  GLenum GetError();
+  GLint GetFragDataLocation(const WebGLProgram&, const std::string& name) const;
+
+  Maybe<double> GetFramebufferAttachmentParameter(WebGLFramebuffer*,
+                                                  GLenum attachment,
+                                                  GLenum pname) const;
+
+  Maybe<double> GetRenderbufferParameter(const WebGLRenderbuffer&,
+                                         GLenum pname) const;
+  webgl::LinkResult GetLinkResult(const WebGLProgram&) const;
+
+  Maybe<webgl::ShaderPrecisionFormat> GetShaderPrecisionFormat(
+      GLenum shadertype, GLenum precisiontype) const;
+
+  webgl::GetUniformData GetUniform(const WebGLProgram&, uint32_t loc) const;
+
+  void Hint(GLenum target, GLenum mode);
+
+  void LineWidth(GLfloat width);
+  void LinkProgram(WebGLProgram& prog);
+  void PolygonOffset(GLfloat factor, GLfloat units);
+  void ProvokingVertex(webgl::ProvokingVertex) const;
+
+  ////
+
+  webgl::PackingInfo ValidImplementationColorReadPI(
+      const webgl::FormatUsageInfo* usage) const;
+
+ protected:
+  webgl::ReadPixelsResult ReadPixelsImpl(const webgl::ReadPixelsDesc&,
+                                         uintptr_t dest, uint64_t availBytes);
+  bool DoReadPixelsAndConvert(const webgl::FormatInfo* srcFormat,
+                              const webgl::ReadPixelsDesc&, uintptr_t dest,
+                              uint64_t dataLen, uint32_t rowStride);
+
+ public:
+  void ReadPixelsPbo(const webgl::ReadPixelsDesc&, uint64_t offset);
+  webgl::ReadPixelsResult ReadPixelsInto(const webgl::ReadPixelsDesc&,
+                                         const Range<uint8_t>& dest);
+
+  ////
+
+  void RenderbufferStorageMultisample(WebGLRenderbuffer&, uint32_t samples,
+                                      GLenum internalformat, uint32_t width,
+                                      uint32_t height) const;
+
+ public:
+  void SampleCoverage(GLclampf value, WebGLboolean invert);
+  void Scissor(GLint x, GLint y, GLsizei width, GLsizei height);
+  void ShaderSource(WebGLShader& shader, const std::string& source) const;
+  void StencilFuncSeparate(GLenum face, GLenum func, GLint ref, GLuint mask);
+  void StencilMaskSeparate(GLenum face, GLuint mask);
+  void StencilOpSeparate(GLenum face, GLenum sfail, GLenum dpfail,
+                         GLenum dppass);
+
+  //////////////////////////
+
+  void UniformData(uint32_t loc, bool transpose,
+                   const Range<const webgl::UniformDataVal>& data) const;
+
+  ////////////////////////////////////
+
+  void UseProgram(WebGLProgram* prog);
+
+  bool ValidateAttribArraySetter(uint32_t count, uint32_t arrayLength);
+  bool ValidateProgram(const WebGLProgram& prog) const;
+  void Viewport(GLint x, GLint y, GLsizei width, GLsizei height);
+
+  // -----------------------------------------------------------------------------
+  // Buffer Objects (WebGLContextBuffers.cpp)
+  void BindBuffer(GLenum target, WebGLBuffer* buffer);
+  void BindBufferRange(GLenum target, GLuint index, WebGLBuffer* buf,
+                       uint64_t offset, uint64_t size);
+
+  void BufferData(GLenum target, uint64_t dataLen, const uint8_t* data,
+                  GLenum usage) const;
+  void UninitializedBufferData_SizeOnly(GLenum target, uint64_t dataLen,
+                                        GLenum usage) const;
+  // The unsynchronized flag may allow for better performance when
+  // interleaving buffer updates with draw calls. However, care must
+  // be taken. This has similar semantics to glMapBufferRange's
+  // GL_MAP_UNSYNCHRONIZED_BIT: the results of any pending operations
+  // that reference the region of the buffer being updated are
+  // undefined.
+  void BufferSubData(GLenum target, uint64_t dstByteOffset, uint64_t srcDataLen,
+                     const uint8_t* srcData, bool unsynchronized = false) const;
+
+ protected:
+  // bound buffer state
+  RefPtr<WebGLBuffer> mBoundArrayBuffer;
+  RefPtr<WebGLBuffer> mBoundCopyReadBuffer;
+  RefPtr<WebGLBuffer> mBoundCopyWriteBuffer;
+  RefPtr<WebGLBuffer> mBoundPixelPackBuffer;
+  RefPtr<WebGLBuffer> mBoundPixelUnpackBuffer;
+  RefPtr<WebGLBuffer> mBoundTransformFeedbackBuffer;
+  RefPtr<WebGLBuffer> mBoundUniformBuffer;
+
+  std::vector<IndexedBufferBinding> mIndexedUniformBufferBindings;
+
+  RefPtr<WebGLBuffer>& GetBufferSlotByTarget(GLenum target);
+  RefPtr<WebGLBuffer>& GetBufferSlotByTargetIndexed(GLenum target,
+                                                    GLuint index);
+
+  // -
+
+  void GenErrorIllegalUse(GLenum useTarget, uint32_t useId, GLenum boundTarget,
+                          uint32_t boundId) const;
+
+  bool ValidateBufferForNonTf(const WebGLBuffer&, GLenum nonTfTarget,
+                              uint32_t nonTfId) const;
+
+  bool ValidateBufferForNonTf(const WebGLBuffer* const nonTfBuffer,
+                              const GLenum nonTfTarget,
+                              const uint32_t nonTfId = -1) const {
+    if (!nonTfBuffer) return true;
+    return ValidateBufferForNonTf(*nonTfBuffer, nonTfTarget, nonTfId);
+  }
+
+  bool ValidateBuffersForTf(const WebGLTransformFeedback&,
+                            const webgl::LinkedProgramInfo&) const;
+  bool ValidateBuffersForTf(
+      const std::vector<webgl::BufferAndIndex>& tfBuffers) const;
+
+  // -----------------------------------------------------------------------------
+  // Queries (WebGL2ContextQueries.cpp)
+ protected:
+  RefPtr<WebGLQuery> mQuerySlot_SamplesPassed;
+  RefPtr<WebGLQuery> mQuerySlot_TFPrimsWritten;
+  RefPtr<WebGLQuery> mQuerySlot_TimeElapsed;
+
+  RefPtr<WebGLQuery>* ValidateQuerySlotByTarget(GLenum target);
+
+ public:
+  void BeginQuery(GLenum target, WebGLQuery& query);
+  void EndQuery(GLenum target);
+  Maybe<double> GetQueryParameter(const WebGLQuery& query, GLenum pname) const;
+  void QueryCounter(WebGLQuery&) const;
+
+  // -----------------------------------------------------------------------------
+  // State and State Requests (WebGLContextState.cpp)
+  void SetEnabled(GLenum cap, Maybe<GLuint> i, bool enabled);
+  bool GetStencilBits(GLint* const out_stencilBits) const;
+
+  virtual Maybe<double> GetParameter(GLenum pname);
+  Maybe<std::string> GetString(GLenum pname) const;
+
+  bool IsEnabled(GLenum cap);
+
+ private:
+  static StaticMutex sLruMutex;
+  static std::list<WebGLContext*> sLru MOZ_GUARDED_BY(sLruMutex);
+
+  // State tracking slots
+  bool mDitherEnabled = true;
+  bool mRasterizerDiscardEnabled = false;
+  bool mScissorTestEnabled = false;
+  bool mDepthTestEnabled = false;
+  bool mStencilTestEnabled = false;
+  GLenum mGenerateMipmapHint = LOCAL_GL_DONT_CARE;
+
+  struct ScissorRect final {
+    GLint x;
+    GLint y;
+    GLsizei w;
+    GLsizei h;
+
+    void Apply(gl::GLContext&) const;
+  };
+  ScissorRect mScissorRect = {};
+
+  bool ValidateCapabilityEnum(GLenum cap);
+  bool* GetStateTrackingSlot(GLenum cap, GLuint i);
+
+  // Allocation debugging variables
+  mutable uint64_t mDataAllocGLCallCount = 0;
+
+  void OnDataAllocCall() const { mDataAllocGLCallCount++; }
+
+  uint64_t GetNumGLDataAllocCalls() const { return mDataAllocGLCallCount; }
+
+  void OnEndOfFrame();
+
+  // -----------------------------------------------------------------------------
+  // Texture funcions (WebGLContextTextures.cpp)
+ public:
+  void ActiveTexture(uint32_t texUnit);
+  void BindTexture(GLenum texTarget, WebGLTexture* tex);
+  void GenerateMipmap(GLenum texTarget);
+
+  Maybe<double> GetTexParameter(const WebGLTexture&, GLenum pname) const;
+  void TexParameter_base(GLenum texTarget, GLenum pname,
+                         const FloatOrInt& param);
+
+  virtual bool IsTexParamValid(GLenum pname) const;
+
+  ////////////////////////////////////
+  // Uploads
+
+  // CompressedTexSubImage if `sub`
+  void CompressedTexImage(bool sub, GLenum imageTarget, uint32_t level,
+                          GLenum format, uvec3 offset, uvec3 size,
+                          const Range<const uint8_t>& src,
+                          const uint32_t pboImageSize,
+                          const Maybe<uint64_t>& pboOffset) const;
+
+  // CopyTexSubImage if `!respectFormat`
+  void CopyTexImage(GLenum imageTarget, uint32_t level, GLenum respecFormat,
+                    uvec3 dstOffset, const ivec2& srcOffset,
+                    const uvec2& size) const;
+
+  // TexSubImage if `!respectFormat`
+  void TexImage(uint32_t level, GLenum respecFormat, uvec3 offset,
+                const webgl::PackingInfo& pi,
+                const webgl::TexUnpackBlobDesc&) const;
+
+  void TexStorage(GLenum texTarget, uint32_t levels, GLenum sizedFormat,
+                  uvec3 size) const;
+
+  UniquePtr<webgl::TexUnpackBlob> ToTexUnpackBytes(
+      const WebGLTexImageData& imageData);
+
+  UniquePtr<webgl::TexUnpackBytes> ToTexUnpackBytes(WebGLTexPboOffset& aPbo);
+
+  ////////////////////////////////////
+  // WebGLTextureUpload.cpp
+ protected:
+  bool ValidateTexImageSpecification(uint8_t funcDims, GLenum texImageTarget,
+                                     GLint level, GLsizei width, GLsizei height,
+                                     GLsizei depth, GLint border,
+                                     TexImageTarget* const out_target,
+                                     WebGLTexture** const out_texture,
+                                     webgl::ImageInfo** const out_imageInfo);
+  bool ValidateTexImageSelection(uint8_t funcDims, GLenum texImageTarget,
+                                 GLint level, GLint xOffset, GLint yOffset,
+                                 GLint zOffset, GLsizei width, GLsizei height,
+                                 GLsizei depth,
+                                 TexImageTarget* const out_target,
+                                 WebGLTexture** const out_texture,
+                                 webgl::ImageInfo** const out_imageInfo);
+  bool ValidateUnpackInfo(bool usePBOs, GLenum format, GLenum type,
+                          webgl::PackingInfo* const out);
+
+  // -----------------------------------------------------------------------------
+  // Vertices Feature (WebGLContextVertices.cpp)
+  GLenum mPrimRestartTypeBytes = 0;
+
+ public:
+  void DrawArraysInstanced(GLenum mode, GLint first, GLsizei vertexCount,
+                           GLsizei instanceCount);
+  void DrawElementsInstanced(GLenum mode, GLsizei vertexCount, GLenum type,
+                             WebGLintptr byteOffset, GLsizei instanceCount);
+
+  void EnableVertexAttribArray(GLuint index);
+  void DisableVertexAttribArray(GLuint index);
+
+  Maybe<double> GetVertexAttrib(GLuint index, GLenum pname);
+
+  ////
+
+  void VertexAttrib4T(GLuint index, const webgl::TypedQuad&);
+
+  ////
+
+  void VertexAttribPointer(uint32_t index, const webgl::VertAttribPointerDesc&);
+
+  void VertexAttribDivisor(GLuint index, GLuint divisor);
+
+ private:
+  WebGLBuffer* DrawElements_check(GLsizei indexCount, GLenum type,
+                                  WebGLintptr byteOffset,
+                                  GLsizei instanceCount);
+  void Draw_cleanup();
+
+  void VertexAttrib1fv_base(GLuint index, uint32_t arrayLength,
+                            const GLfloat* ptr);
+  void VertexAttrib2fv_base(GLuint index, uint32_t arrayLength,
+                            const GLfloat* ptr);
+  void VertexAttrib3fv_base(GLuint index, uint32_t arrayLength,
+                            const GLfloat* ptr);
+  void VertexAttrib4fv_base(GLuint index, uint32_t arrayLength,
+                            const GLfloat* ptr);
+
+  bool BindArrayAttribToLocation0(WebGLProgram* prog);
+
+  // -----------------------------------------------------------------------------
+  // PROTECTED
+ protected:
+  WebGLVertexAttrib0Status WhatDoesVertexAttrib0Need() const;
+  bool DoFakeVertexAttrib0(uint64_t fakeVertexCount,
+                           WebGLVertexAttrib0Status whatDoesAttrib0Need);
+  void UndoFakeVertexAttrib0();
+
+  bool mResetLayer = true;
+  bool mOptionsFrozen = false;
+  bool mIsMesa = false;
+  bool mLoseContextOnMemoryPressure = false;
+  bool mCanLoseContextInForeground = true;
+  bool mShouldPresent = false;
+  bool mDisableFragHighP = false;
+  bool mForceResizeOnPresent = false;
+  bool mVRReady = false;
+
+  template <typename WebGLObjectType>
+  void DeleteWebGLObjectsArray(nsTArray<WebGLObjectType>& array);
+
+  GLuint mActiveTexture = 0;
+  GLenum mDefaultFB_DrawBuffer0 = LOCAL_GL_BACK;
+  GLenum mDefaultFB_ReadBuffer = LOCAL_GL_BACK;
+
+  mutable GLenum mWebGLError = 0;
+
+  std::unique_ptr<webgl::ShaderValidator> CreateShaderValidator(
+      GLenum shaderType) const;
+
+  // some GL constants
+  uint32_t mGLMaxFragmentUniformVectors = 0;
+  uint32_t mGLMaxVertexUniformVectors = 0;
+  uint32_t mGLMaxVertexOutputVectors = 0;
+  uint32_t mGLMaxFragmentInputVectors = 0;
+
+  uint32_t mGLMaxVertexTextureImageUnits = 0;
+  uint32_t mGLMaxFragmentTextureImageUnits = 0;
+  uint32_t mGLMaxCombinedTextureImageUnits = 0;
+
+  // ES3:
+  uint32_t mGLMinProgramTexelOffset = 0;
+  uint32_t mGLMaxProgramTexelOffset = 0;
+
+ public:
+  auto GLMaxDrawBuffers() const { return mLimits->maxColorDrawBuffers; }
+
+  uint32_t MaxValidDrawBuffers() const {
+    if (IsWebGL2() ||
+        IsExtensionEnabled(WebGLExtensionID::WEBGL_draw_buffers)) {
+      return GLMaxDrawBuffers();
+    }
+    return 1;
+  }
+
+  GLenum LastColorAttachmentEnum() const {
+    return LOCAL_GL_COLOR_ATTACHMENT0 + MaxValidDrawBuffers() - 1;
+  }
+
+  const auto& Options() const { return mOptions; }
+
+ protected:
+  uint32_t mGLMaxRenderbufferSize = 0;
+
+ public:
+  const auto& Limits() const { return *mLimits; }
+  auto MaxVertexAttribs() const { return mLimits->maxVertexAttribs; }
+  auto GLMaxTextureUnits() const { return mLimits->maxTexUnits; }
+
+  bool IsFormatValidForFB(TexInternalFormat format) const;
+
+ protected:
+  // -------------------------------------------------------------------------
+  // WebGL extensions (implemented in WebGLContextExtensions.cpp)
+
+  EnumeratedArray<WebGLExtensionID, WebGLExtensionID::Max,
+                  std::unique_ptr<WebGLExtensionBase>>
+      mExtensions;
+
+ public:
+  void RequestExtension(WebGLExtensionID, bool explicitly = true);
+
+  // returns true if the extension has been enabled by calling getExtension.
+  bool IsExtensionEnabled(const WebGLExtensionID id) const {
+    return bool(mExtensions[id]);
+  }
+
+  bool IsExtensionExplicit(WebGLExtensionID) const;
+  void WarnIfImplicit(WebGLExtensionID) const;
+
+  bool IsExtensionSupported(WebGLExtensionID) const;
+
+  // -------------------------------------------------------------------------
+  // WebGL 2 specifics (implemented in WebGL2Context.cpp)
+ public:
+  virtual bool IsWebGL2() const { return false; }
+
+  struct FailureReason {
+    nsCString key;  // For reporting.
+    nsCString info;
+
+    FailureReason() = default;
+
+    template <typename A, typename B>
+    FailureReason(const A& _key, const B& _info)
+        : key(nsCString(_key)), info(nsCString(_info)) {}
+  };
+
+ protected:
+  bool InitWebGL2(FailureReason* const out_failReason);
+
+  bool CreateAndInitGL(bool forceEnabled,
+                       std::vector<FailureReason>* const out_failReasons);
+
+  // -------------------------------------------------------------------------
+  // Validation functions (implemented in WebGLContextValidate.cpp)
+  bool InitAndValidateGL(FailureReason* const out_failReason);
+
+  bool ValidateBlendEquationEnum(GLenum cap, const char* info);
+  bool ValidateBlendFuncEnumsCompatibility(GLenum sfactor, GLenum dfactor,
+                                           const char* info);
+  bool ValidateStencilOpEnum(GLenum action, const char* info);
+  bool ValidateFaceEnum(GLenum face);
+  bool ValidateTexInputData(GLenum type, js::Scalar::Type jsArrayType,
+                            WebGLTexImageFunc func, WebGLTexDimensions dims);
+  bool ValidateAttribPointer(bool integerMode, GLuint index, GLint size,
+                             GLenum type, WebGLboolean normalized,
+                             GLsizei stride, WebGLintptr byteOffset,
+                             const char* info);
+  bool ValidateStencilParamsForDrawCall() const;
+
+  bool ValidateCopyTexImage(TexInternalFormat srcFormat,
+                            TexInternalFormat dstformat, WebGLTexImageFunc func,
+                            WebGLTexDimensions dims);
+
+  bool ValidateTexImage(TexImageTarget texImageTarget, GLint level,
+                        GLenum internalFormat, GLint xoffset, GLint yoffset,
+                        GLint zoffset, GLint width, GLint height, GLint depth,
+                        GLint border, GLenum format, GLenum type,
+                        WebGLTexImageFunc func, WebGLTexDimensions dims);
+  bool ValidateTexImageFormat(GLenum internalFormat, WebGLTexImageFunc func,
+                              WebGLTexDimensions dims);
+  bool ValidateTexImageType(GLenum type, WebGLTexImageFunc func,
+                            WebGLTexDimensions dims);
+  bool ValidateTexImageFormatAndType(GLenum format, GLenum type,
+                                     WebGLTexImageFunc func,
+                                     WebGLTexDimensions dims);
+  bool ValidateCompTexImageInternalFormat(GLenum format, WebGLTexImageFunc func,
+                                          WebGLTexDimensions dims);
+  bool ValidateCopyTexImageInternalFormat(GLenum format, WebGLTexImageFunc func,
+                                          WebGLTexDimensions dims);
+  bool ValidateTexImageSize(TexImageTarget texImageTarget, GLint level,
+                            GLint width, GLint height, GLint depth,
+                            WebGLTexImageFunc func, WebGLTexDimensions dims);
+  bool ValidateTexSubImageSize(GLint x, GLint y, GLint z, GLsizei width,
+                               GLsizei height, GLsizei depth, GLsizei baseWidth,
+                               GLsizei baseHeight, GLsizei baseDepth,
+                               WebGLTexImageFunc func, WebGLTexDimensions dims);
+  bool ValidateCompTexImageSize(GLint level, GLenum internalFormat,
+                                GLint xoffset, GLint yoffset, GLsizei width,
+                                GLsizei height, GLsizei levelWidth,
+                                GLsizei levelHeight, WebGLTexImageFunc func,
+                                WebGLTexDimensions dims);
+  bool ValidateCompTexImageDataSize(GLint level, GLenum internalFormat,
+                                    GLsizei width, GLsizei height,
+                                    uint32_t byteLength, WebGLTexImageFunc func,
+                                    WebGLTexDimensions dims);
+
+  bool HasDrawBuffers() const {
+    return IsWebGL2() ||
+           IsExtensionEnabled(WebGLExtensionID::WEBGL_draw_buffers);
+  }
+
+  RefPtr<WebGLBuffer>* ValidateBufferSlot(GLenum target);
+
+ public:
+  WebGLBuffer* ValidateBufferSelection(GLenum target) const;
+
+ protected:
+  IndexedBufferBinding* ValidateIndexedBufferSlot(GLenum target, GLuint index);
+
+  bool ValidateIndexedBufferBinding(
+      GLenum target, GLuint index,
+      RefPtr<WebGLBuffer>** const out_genericBinding,
+      IndexedBufferBinding** const out_indexedBinding);
+
+ public:
+  bool ValidateNonNegative(const char* argName, int64_t val) const {
+    if (MOZ_UNLIKELY(val < 0)) {
+      ErrorInvalidValue("`%s` must be non-negative.", argName);
+      return false;
+    }
+    return true;
+  }
+
+  template <typename T>
+  bool ValidateNonNull(const char* const argName,
+                       const dom::Nullable<T>& maybe) const {
+    if (maybe.IsNull()) {
+      ErrorInvalidValue("%s: Cannot be null.", argName);
+      return false;
+    }
+    return true;
+  }
+
+  ////
+
+ protected:
+  void DestroyResourcesAndContext();
+
+  // helpers
+
+  bool ConvertImage(size_t width, size_t height, size_t srcStride,
+                    size_t dstStride, const uint8_t* src, uint8_t* dst,
+                    WebGLTexelFormat srcFormat, bool srcPremultiplied,
+                    WebGLTexelFormat dstFormat, bool dstPremultiplied,
+                    size_t dstTexelSize);
+
+  //////
+ public:
+  template <typename T>
+  bool ValidateObject(const char* const argName, const T& object) const {
+    // Todo: Remove all callers.
+    return true;
+  }
+
+  template <typename T>
+  bool ValidateObject(const char* const argName, const T* const object) const {
+    // Todo: Remove most (all?) callers.
+    if (!object) {
+      ErrorInvalidOperation(
+          "%s: Object argument cannot have been marked for"
+          " deletion.",
+          argName);
+      return false;
+    }
+    return true;
+  }
+
+  ////
+
+ private:
+  void LoseContextLruLocked(webgl::ContextLossReason reason)
+      MOZ_REQUIRES(sLruMutex);
+
+ public:
+  void LoseContext(
+      webgl::ContextLossReason reason = webgl::ContextLossReason::None);
+
+ protected:
+  nsTArray<RefPtr<WebGLTexture>> mBound2DTextures;
+  nsTArray<RefPtr<WebGLTexture>> mBoundCubeMapTextures;
+  nsTArray<RefPtr<WebGLTexture>> mBound3DTextures;
+  nsTArray<RefPtr<WebGLTexture>> mBound2DArrayTextures;
+  nsTArray<RefPtr<WebGLSampler>> mBoundSamplers;
+
+  void ResolveTexturesForDraw() const;
+
+  RefPtr<WebGLProgram> mCurrentProgram;
+  RefPtr<const webgl::LinkedProgramInfo> mActiveProgramLinkInfo;
+
+  bool ValidateFramebufferTarget(GLenum target) const;
+  bool ValidateInvalidateFramebuffer(GLenum target,
+                                     const Range<const GLenum>& attachments,
+                                     std::vector<GLenum>* const scopedVector,
+                                     GLsizei* const out_glNumAttachments,
+                                     const GLenum** const out_glAttachments);
+
+  RefPtr<WebGLFramebuffer> mBoundDrawFramebuffer;
+  RefPtr<WebGLFramebuffer> mBoundReadFramebuffer;
+  RefPtr<WebGLTransformFeedback> mBoundTransformFeedback;
+  RefPtr<WebGLVertexArray> mBoundVertexArray;
+
+ public:
+  const auto& BoundReadFb() const { return mBoundReadFramebuffer; }
+
+ protected:
+  RefPtr<WebGLTransformFeedback> mDefaultTransformFeedback;
+  RefPtr<WebGLVertexArray> mDefaultVertexArray;
+
+  ////////////////////////////////////
+
+ protected:
+  GLuint mEmptyTFO = 0;
+
+  // Generic Vertex Attributes
+  // Though CURRENT_VERTEX_ATTRIB is listed under "Vertex Shader State" in the
+  // spec state tables, this isn't vertex shader /object/ state. This array is
+  // merely state useful to vertex shaders, but is global state.
+  std::vector<webgl::AttribBaseType> mGenericVertexAttribTypes;
+  CacheInvalidator mGenericVertexAttribTypeInvalidator;
+
+  GLuint mFakeVertexAttrib0BufferObject = 0;
+  intptr_t mFakeVertexAttrib0BufferObjectSize = 0;
+  bool mFakeVertexAttrib0DataDefined = false;
+  alignas(alignof(float)) uint8_t
+      mGenericVertexAttrib0Data[sizeof(float) * 4] = {};
+  alignas(alignof(float)) uint8_t
+      mFakeVertexAttrib0Data[sizeof(float) * 4] = {};
+
+  GLint mStencilRefFront = 0;
+  GLint mStencilRefBack = 0;
+  GLuint mStencilValueMaskFront = 0;
+  GLuint mStencilValueMaskBack = 0;
+  GLuint mStencilWriteMaskFront = 0;
+  GLuint mStencilWriteMaskBack = 0;
+  uint8_t mColorWriteMask0 = 0xf;  // bitmask
+  mutable uint8_t mDriverColorMask0 = 0xf;
+  bool mDepthWriteMask = true;
+  GLfloat mColorClearValue[4] = {0, 0, 0, 0};
+  GLint mStencilClearValue = 0;
+  GLfloat mDepthClearValue = 1.0f;
+
+  std::bitset<webgl::kMaxDrawBuffers> mColorWriteMaskNonzero = -1;
+  std::bitset<webgl::kMaxDrawBuffers> mBlendEnabled = 0;
+
+  GLint mViewportX = 0;
+  GLint mViewportY = 0;
+  GLsizei mViewportWidth = 0;
+  GLsizei mViewportHeight = 0;
+  bool mAlreadyWarnedAboutViewportLargerThanDest = false;
+
+  GLfloat mLineWidth = 1.0;
+
+  WebGLContextLossHandler mContextLossHandler;
+
+  // Used for some hardware (particularly Tegra 2 and 4) that likes to
+  // be Flushed while doing hundreds of draw calls.
+  mutable uint64_t mDrawCallsSinceLastFlush = 0;
+
+  mutable uint64_t mWarningCount = 0;
+  const uint64_t mMaxWarnings = StaticPrefs::webgl_max_warnings_per_context();
+  bool mAlreadyWarnedAboutFakeVertexAttrib0 = false;
+
+  bool ShouldGenerateWarnings() const { return mWarningCount < mMaxWarnings; }
+
+  bool ShouldGeneratePerfWarnings() const {
+    return mNumPerfWarnings < mMaxPerfWarnings;
+  }
+
+  bool mNeedsFakeNoAlpha = false;
+  bool mNeedsFakeNoDepth = false;
+  bool mNeedsFakeNoStencil = false;
+
+  bool mDriverDepthTest = false;
+  bool mDriverStencilTest = false;
+
+  bool mNeedsLegacyVertexAttrib0Handling = false;
+  bool mMaybeNeedsLegacyVertexAttrib0Handling = false;
+  bool mNeedsIndexValidation = false;
+  bool mBug_DrawArraysInstancedUserAttribFetchAffectedByFirst = false;
+
+  const bool mAllowFBInvalidation = StaticPrefs::webgl_allow_fb_invalidation();
+
+  bool Has64BitTimestamps() const;
+
+  // --
+
+  const uint8_t mMsaaSamples =
+      static_cast<uint8_t>(StaticPrefs::webgl_msaa_samples());
+  mutable uvec2 mRequestedSize;
+  mutable UniquePtr<gl::MozFramebuffer> mDefaultFB;
+  mutable bool mDefaultFB_IsInvalid = false;
+  mutable UniquePtr<gl::MozFramebuffer> mResolvedDefaultFB;
+
+  gl::SwapChain mSwapChain;
+  gl::SwapChain mWebVRSwapChain;
+
+  RefPtr<layers::RemoteTextureOwnerClient> mRemoteTextureOwner;
+
+  bool PushRemoteTexture(
+      WebGLFramebuffer*, gl::SwapChain&, std::shared_ptr<gl::SharedSurface>,
+      const webgl::SwapChainOptions& options,
+      layers::RemoteTextureOwnerClient* ownerClient = nullptr);
+
+  void EnsureContextLostRemoteTextureOwner(
+      const webgl::SwapChainOptions& options);
+
+ public:
+  void WaitForTxn(layers::RemoteTextureOwnerId ownerId,
+                  layers::RemoteTextureTxnType txnType,
+                  layers::RemoteTextureTxnId txnId);
+
+  // --
+
+ protected:
+  bool EnsureDefaultFB();
+  bool ValidateAndInitFB(
+      const WebGLFramebuffer* fb,
+      GLenum incompleteFbError = LOCAL_GL_INVALID_FRAMEBUFFER_OPERATION);
+  void DoBindFB(const WebGLFramebuffer* fb,
+                GLenum target = LOCAL_GL_FRAMEBUFFER) const;
+
+  bool BindCurFBForDraw();
+  bool BindCurFBForColorRead(
+      const webgl::FormatUsageInfo** out_format, uint32_t* out_width,
+      uint32_t* out_height,
+      GLenum incompleteFbError = LOCAL_GL_INVALID_FRAMEBUFFER_OPERATION);
+  void DoColorMask(Maybe<GLuint> i, uint8_t bitmask) const;
+  void BlitBackbufferToCurDriverFB(
+      WebGLFramebuffer* const srcAsWebglFb = nullptr,
+      const gl::MozFramebuffer* const srcAsMozFb = nullptr,
+      bool srcIsBGRA = false) const;
+  bool BindDefaultFBForRead();
+
+  // --
+
+ public:
+  // console logging helpers
+  template <typename... Args>
+  void GenerateWarning(const char* const fmt, const Args&... args) const {
+    GenerateError(0, fmt, args...);
+  }
+
+  template <typename... Args>
+  void GeneratePerfWarning(const char* const fmt, const Args&... args) const {
+    GenerateError(webgl::kErrorPerfWarning, fmt, args...);
+  }
+
+ public:
+  UniquePtr<webgl::FormatUsageAuthority> mFormatUsage;
+
+  virtual UniquePtr<webgl::FormatUsageAuthority> CreateFormatUsage(
+      gl::GLContext* gl) const;
+
+  const decltype(mBound2DTextures)* TexListForElemType(GLenum elemType) const;
+
+  // Friend list
+  friend class ScopedCopyTexImageSource;
+  friend class ScopedResolveTexturesForDraw;
+  friend class webgl::TexUnpackBlob;
+  friend class webgl::TexUnpackBytes;
+  friend class webgl::TexUnpackImage;
+  friend class webgl::TexUnpackSurface;
+  friend struct webgl::UniformInfo;
+  friend class WebGLTexture;
+  friend class WebGLFBAttachPoint;
+  friend class WebGLFramebuffer;
+  friend class WebGLRenderbuffer;
+  friend class WebGLProgram;
+  friend class WebGLQuery;
+  friend class WebGLBuffer;
+  friend class WebGLSampler;
+  friend class WebGLShader;
+  friend class WebGLSync;
+  friend class WebGLTransformFeedback;
+  friend class WebGLVertexArray;
+  friend class WebGLVertexArrayFake;
+  friend class WebGLVertexArrayGL;
+};
+
+// Returns `value` rounded to the next highest multiple of `multiple`.
+// AKA PadToAlignment, StrideForAlignment.
+template <typename V, typename M>
+V RoundUpToMultipleOf(const V& value, const M& multiple) {
+  return ((value + multiple - 1) / multiple) * multiple;
+}
+
+class ScopedFBRebinder final {
+ private:
+  const WebGLContext* const mWebGL;
+
+ public:
+  explicit ScopedFBRebinder(const WebGLContext* const webgl) : mWebGL(webgl) {}
+  ~ScopedFBRebinder();
+};
+
+// -
+
+constexpr inline bool IsBufferTargetLazilyBound(const GLenum target) {
+  return target != LOCAL_GL_ELEMENT_ARRAY_BUFFER;
+}
+
+void DoBindBuffer(gl::GLContext&, GLenum target, const WebGLBuffer*);
+
+class ScopedLazyBind final {
+ private:
+  gl::GLContext& mGL;
+  const GLenum mTarget;
+
+ public:
+  ScopedLazyBind(gl::GLContext* const gl, const GLenum target,
+                 const WebGLBuffer* const buf)
+      : mGL(*gl), mTarget(IsBufferTargetLazilyBound(target) ? target : 0) {
+    if (mTarget) {
+      DoBindBuffer(mGL, mTarget, buf);
+    }
+  }
+
+  ~ScopedLazyBind() {
+    if (mTarget) {
+      DoBindBuffer(mGL, mTarget, nullptr);
+    }
+  }
+};
+
+////
+
+bool Intersect(int32_t srcSize, int32_t read0, int32_t readSize,
+               int32_t* out_intRead0, int32_t* out_intWrite0,
+               int32_t* out_intSize);
+
+uint64_t AvailGroups(uint64_t totalAvailItems, uint64_t firstItemOffset,
+                     uint32_t groupSize, uint32_t groupStride);
+
+////
+
+class ScopedDrawCallWrapper final {
+ public:
+  WebGLContext& mWebGL;
+
+  explicit ScopedDrawCallWrapper(WebGLContext& webgl);
+  ~ScopedDrawCallWrapper();
+};
+
+namespace webgl {
+
+class ScopedPrepForResourceClear final {
+  const WebGLContext& webgl;
+
+ public:
+  explicit ScopedPrepForResourceClear(const WebGLContext&);
+  ~ScopedPrepForResourceClear();
+};
+
+struct IndexedName final {
+  std::string name;
+  uint64_t index;
+};
+Maybe<IndexedName> ParseIndexed(const std::string& str);
+
+}  // namespace webgl
+
+webgl::LinkActiveInfo GetLinkActiveInfo(
+    gl::GLContext& gl, const GLuint prog, const bool webgl2,
+    const std::unordered_map<std::string, std::string>& nameUnmap);
+
+}  // namespace mozilla
+
+#endif