--- a/dom/canvas/WebGLContext.cpp
+++ b/dom/canvas/WebGLContext.cpp
@@ -2174,18 +2174,18 @@ ZeroTexImageWithClear(WebGLContext* webg
             return false;
         }
     }
 
     return true;
 }
 
 bool
-ZeroTextureData(WebGLContext* webgl, const char* funcName, bool respecifyTexture,
-                GLuint tex, TexImageTarget target, uint32_t level,
+ZeroTextureData(WebGLContext* webgl, const char* funcName, GLuint tex,
+                TexImageTarget target, uint32_t level,
                 const webgl::FormatUsageInfo* usage, uint32_t xOffset, uint32_t yOffset,
                 uint32_t zOffset, uint32_t width, uint32_t height, uint32_t depth)
 {
     // This has two usecases:
     // 1. Lazy zeroing of uninitialized textures:
     //    a. Before draw, when FakeBlack isn't viable. (TexStorage + Draw*)
     //    b. Before partial upload. (TexStorage + TexSubImage)
     // 2. Zero subrects from out-of-bounds blits. (CopyTex(Sub)Image)
@@ -2198,17 +2198,16 @@ ZeroTextureData(WebGLContext* webgl, con
                            funcName);
 
     gl::GLContext* gl = webgl->GL();
     gl->MakeCurrent();
 
     auto compression = usage->format->compression;
     if (compression) {
         MOZ_RELEASE_ASSERT(!xOffset && !yOffset && !zOffset, "GFX: Can't zero compressed texture with offsets.");
-        MOZ_RELEASE_ASSERT(!respecifyTexture, "GFX: respecifyTexture is set to true.");
 
         auto sizedFormat = usage->format->sizedFormat;
         MOZ_RELEASE_ASSERT(sizedFormat, "GFX: texture sized format not set");
 
         const auto fnSizeInBlocks = [](CheckedUint32 pixels, uint8_t pixelsPerBlock) {
             return RoundUpToMultipleOf(pixels, pixelsPerBlock) / pixelsPerBlock;
         };
 
@@ -2246,23 +2245,16 @@ ZeroTextureData(WebGLContext* webgl, con
     MOZ_RELEASE_ASSERT(driverUnpackInfo, "GFX: ideal unpack info not set.");
 
     if (usage->IsRenderable() && depth == 1 &&
         !xOffset && !yOffset && !zOffset)
     {
         // While we would like to skip the extra complexity of trying to zero with an FB
         // clear, ANGLE_depth_texture requires this.
         do {
-            if (respecifyTexture) {
-                const auto error = DoTexImage(gl, target, level, driverUnpackInfo, width,
-                                              height, depth, nullptr);
-                if (error)
-                    break;
-            }
-
             if (ZeroTexImageWithClear(webgl, gl, target, tex, level, usage, width,
                                       height))
             {
                 return true;
             }
         } while (false);
     }
 
@@ -2282,25 +2274,18 @@ ZeroTextureData(WebGLContext* webgl, con
 
     UniqueBuffer zeros = calloc(1, byteCount);
     if (!zeros)
         return false;
 
     ScopedUnpackReset scopedReset(webgl);
     gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 1); // Don't bother with striding it well.
 
-    GLenum error;
-    if (respecifyTexture) {
-        MOZ_RELEASE_ASSERT(!xOffset && !yOffset && !zOffset, "GFX: texture data, offsets, not zeroed.");
-        error = DoTexImage(gl, target, level, driverUnpackInfo, width, height, depth,
-                           zeros.get());
-    } else {
-        error = DoTexSubImage(gl, target, level, xOffset, yOffset, zOffset, width, height,
-                              depth, packing, zeros.get());
-    }
+    const auto error = DoTexSubImage(gl, target, level, xOffset, yOffset, zOffset, width,
+                                     height, depth, packing, zeros.get());
     if (error)
         return false;
 
     return true;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 

--- a/dom/canvas/WebGLContext.h
+++ b/dom/canvas/WebGLContext.h
@@ -1751,16 +1751,16 @@ ComputeLengthAndData(const dom::ArrayBuf
                      js::Scalar::Type* const out_type);
 
 void
 Intersect(uint32_t srcSize, int32_t dstStartInSrc, uint32_t dstSize,
           uint32_t* const out_intStartInSrc, uint32_t* const out_intStartInDst,
           uint32_t* const out_intSize);
 
 bool
-ZeroTextureData(WebGLContext* webgl, const char* funcName, bool respecifyTexture,
-                GLuint tex, TexImageTarget target, uint32_t level,
+ZeroTextureData(WebGLContext* webgl, const char* funcName, GLuint tex,
+                TexImageTarget target, uint32_t level,
                 const webgl::FormatUsageInfo* usage, uint32_t xOffset, uint32_t yOffset,
                 uint32_t zOffset, uint32_t width, uint32_t height, uint32_t depth);
 
 } // namespace mozilla
 
 #endif

--- a/dom/canvas/WebGLTexture.cpp
+++ b/dom/canvas/WebGLTexture.cpp
@@ -586,24 +586,23 @@ WebGLTexture::EnsureImageDataInitialized
 bool
 WebGLTexture::InitializeImageData(const char* funcName, TexImageTarget target,
                                   uint32_t level)
 {
     auto& imageInfo = ImageInfoAt(target, level);
     MOZ_ASSERT(imageInfo.IsDefined());
     MOZ_ASSERT(!imageInfo.IsDataInitialized());
 
-    const bool respecifyTexture = false;
     const auto& usage = imageInfo.mFormat;
     const auto& width = imageInfo.mWidth;
     const auto& height = imageInfo.mHeight;
     const auto& depth = imageInfo.mDepth;
 
-    if (!ZeroTextureData(mContext, funcName, respecifyTexture, mGLName, target, level,
-                         usage, 0, 0, 0, width, height, depth))
+    if (!ZeroTextureData(mContext, funcName, mGLName, target, level, usage, 0, 0, 0,
+                         width, height, depth))
     {
         return false;
     }
 
     imageInfo.SetIsDataInitialized(true, this);
     return true;
 }
 

--- a/dom/canvas/WebGLTextureUpload.cpp
+++ b/dom/canvas/WebGLTextureUpload.cpp
@@ -2074,20 +2074,19 @@ WebGLTexture::CopyTexImage2D(TexImageTar
 
     GLenum error;
     if (rwWidth == uint32_t(width) && rwHeight == uint32_t(height)) {
         error = DoCopyTexImage2D(gl, target, level, internalFormat, x, y, width, height);
     } else {
         // 1. Zero the texture data.
         // 2. CopyTexSubImage the subrect.
 
-        const bool respecifyTexture = true;
         const uint8_t zOffset = 0;
-        if (!ZeroTextureData(mContext, funcName, respecifyTexture, mGLName, target, level,
-                             dstUsage, 0, 0, zOffset, width, height, depth))
+        if (!ZeroTextureData(mContext, funcName, mGLName, target, level, dstUsage, 0, 0,
+                             zOffset, width, height, depth))
         {
             mContext->ErrorOutOfMemory("%s: Failed to zero texture data.", funcName);
             MOZ_ASSERT(false, "Failed to zero texture data.");
             return;
         }
 
         if (!rwWidth || !rwHeight) {
             // There aren't any, so we're 'done'.