--- a/dom/canvas/WebGLExtensionTextureFloat.cpp
+++ b/dom/canvas/WebGLExtensionTextureFloat.cpp
@@ -36,66 +36,58 @@ WebGLExtensionTextureFloat::WebGLExtensi
     MOZ_ASSERT_IF(needsSwizzle, gl->IsSupported(gl::GLFeature::texture_swizzle));
 
     const bool needsSizedFormat = !gl->IsGLES();
 
     ////////////////
 
     pi = {LOCAL_GL_RGBA, LOCAL_GL_FLOAT};
     dui = {pi.format, pi.format, pi.type};
-    swizzle = nullptr;
     if (needsSizedFormat) {
         dui.internalFormat = LOCAL_GL_RGBA32F;
     }
     fnAdd(webgl::EffectiveFormat::RGBA32F);
 
     //////
 
     pi = {LOCAL_GL_RGB, LOCAL_GL_FLOAT};
     dui = {pi.format, pi.format, pi.type};
-    swizzle = nullptr;
     if (needsSizedFormat) {
         dui.internalFormat = LOCAL_GL_RGB32F;
     }
     fnAdd(webgl::EffectiveFormat::RGB32F);
 
     //////
 
     pi = {LOCAL_GL_LUMINANCE, LOCAL_GL_FLOAT};
     dui = {pi.format, pi.format, pi.type};
-    swizzle = nullptr;
     if (needsSwizzle) {
         dui = {LOCAL_GL_R32F, LOCAL_GL_RED, LOCAL_GL_FLOAT};
-        swizzle = webgl::FormatUsageInfo::kLuminanceSwizzleRGBA;
     } else if (needsSizedFormat) {
         dui.internalFormat = LOCAL_GL_LUMINANCE32F_ARB;
     }
     fnAdd(webgl::EffectiveFormat::Luminance32F);
 
     //////
 
     pi = {LOCAL_GL_ALPHA, LOCAL_GL_FLOAT};
     dui = {pi.format, pi.format, pi.type};
-    swizzle = nullptr;
     if (needsSwizzle) {
         dui = {LOCAL_GL_R32F, LOCAL_GL_RED, LOCAL_GL_FLOAT};
-        swizzle = webgl::FormatUsageInfo::kAlphaSwizzleRGBA;
     } else if (needsSizedFormat) {
         dui.internalFormat = LOCAL_GL_ALPHA32F_ARB;
     }
     fnAdd(webgl::EffectiveFormat::Alpha32F);
 
     //////
 
     pi = {LOCAL_GL_LUMINANCE_ALPHA, LOCAL_GL_FLOAT};
     dui = {pi.format, pi.format, pi.type};
-    swizzle = nullptr;
     if (needsSwizzle) {
         dui = {LOCAL_GL_RG32F, LOCAL_GL_RG, LOCAL_GL_FLOAT};
-        swizzle = webgl::FormatUsageInfo::kLumAlphaSwizzleRGBA;
     } else if (needsSizedFormat) {
         dui.internalFormat = LOCAL_GL_LUMINANCE_ALPHA32F_ARB;
     }
     fnAdd(webgl::EffectiveFormat::Luminance32FAlpha32F);
 }
 
 WebGLExtensionTextureFloat::~WebGLExtensionTextureFloat()
 {

--- a/dom/canvas/WebGLExtensionTextureHalfFloat.cpp
+++ b/dom/canvas/WebGLExtensionTextureHalfFloat.cpp
@@ -40,66 +40,58 @@ WebGLExtensionTextureHalfFloat::WebGLExt
         MOZ_ASSERT(gl->IsExtensionSupported(gl::GLContext::OES_texture_half_float));
         driverUnpackType = LOCAL_GL_HALF_FLOAT_OES;
     }
 
     ////////////////
 
     pi = {LOCAL_GL_RGBA, LOCAL_GL_HALF_FLOAT_OES};
     dui = {pi.format, pi.format, driverUnpackType};
-    swizzle = nullptr;
     if (needsSizedFormat) {
         dui.internalFormat = LOCAL_GL_RGBA16F;
     }
     fnAdd(webgl::EffectiveFormat::RGBA16F);
 
     //////
 
     pi = {LOCAL_GL_RGB, LOCAL_GL_HALF_FLOAT_OES};
     dui = {pi.format, pi.format, driverUnpackType};
-    swizzle = nullptr;
     if (needsSizedFormat) {
         dui.internalFormat = LOCAL_GL_RGB16F;
     }
     fnAdd(webgl::EffectiveFormat::RGB16F);
 
     //////
 
     pi = {LOCAL_GL_LUMINANCE, LOCAL_GL_HALF_FLOAT_OES};
     dui = {pi.format, pi.format, driverUnpackType};
-    swizzle = nullptr;
     if (needsSwizzle) {
         dui = {LOCAL_GL_R16F, LOCAL_GL_RED, driverUnpackType};
-        swizzle = webgl::FormatUsageInfo::kLuminanceSwizzleRGBA;
     } else if (needsSizedFormat) {
         dui.internalFormat = LOCAL_GL_LUMINANCE16F_ARB;
     }
     fnAdd(webgl::EffectiveFormat::Luminance16F);
 
     //////
 
     pi = {LOCAL_GL_ALPHA, LOCAL_GL_HALF_FLOAT_OES};
     dui = {pi.format, pi.format, driverUnpackType};
-    swizzle = nullptr;
     if (needsSwizzle) {
         dui = {LOCAL_GL_R16F, LOCAL_GL_RED, driverUnpackType};
-        swizzle = webgl::FormatUsageInfo::kAlphaSwizzleRGBA;
     } else if (needsSizedFormat) {
         dui.internalFormat = LOCAL_GL_ALPHA16F_ARB;
     }
     fnAdd(webgl::EffectiveFormat::Alpha16F);
 
     //////
 
     pi = {LOCAL_GL_LUMINANCE_ALPHA, LOCAL_GL_HALF_FLOAT_OES};
     dui = {pi.format, pi.format, driverUnpackType};
-    swizzle = nullptr;
     if (needsSwizzle) {
         dui = {LOCAL_GL_RG16F, LOCAL_GL_RG, driverUnpackType};
-        swizzle = webgl::FormatUsageInfo::kLumAlphaSwizzleRGBA;
     } else if (needsSizedFormat) {
         dui.internalFormat = LOCAL_GL_LUMINANCE_ALPHA16F_ARB;
     }
     fnAdd(webgl::EffectiveFormat::Luminance16FAlpha16F);
 }
 
 WebGLExtensionTextureHalfFloat::~WebGLExtensionTextureHalfFloat()
 {