diff --git a/content/canvas/src/WebGLContext.cpp b/content/canvas/src/WebGLContext.cpp
index 4d8e2531b3a3..7ae9a2ba125f 100644
--- a/content/canvas/src/WebGLContext.cpp
+++ b/content/canvas/src/WebGLContext.cpp
@@ -113,11 +113,17 @@ WebGLContext::WebGLContext()
     mBlackTexturesAreInitialized = PR_FALSE;
     mFakeBlackStatus = DoNotNeedFakeBlack;
 
-    mFakeVertexAttrib0Array = nsnull;
     mVertexAttrib0Vector[0] = 0;
     mVertexAttrib0Vector[1] = 0;
     mVertexAttrib0Vector[2] = 0;
     mVertexAttrib0Vector[3] = 1;
+    mFakeVertexAttrib0BufferObjectVector[0] = 0;
+    mFakeVertexAttrib0BufferObjectVector[1] = 0;
+    mFakeVertexAttrib0BufferObjectVector[2] = 0;
+    mFakeVertexAttrib0BufferObjectVector[3] = 1;
+    mFakeVertexAttrib0BufferObjectSize = 0;
+    mFakeVertexAttrib0BufferObject = 0;
+    mFakeVertexAttrib0BufferStatus = VertexAttrib0Status::Default;
 }
 
 WebGLContext::~WebGLContext()
@@ -223,6 +229,10 @@ WebGLContext::DestroyResourcesAndContext()
         mBlackTexturesAreInitialized = PR_FALSE;
     }
 
+    if (mFakeVertexAttrib0BufferObject) {
+        gl->fDeleteBuffers(1, &mFakeVertexAttrib0BufferObject);
+    }
+
     // We just got rid of everything, so the context had better
     // have been going away.
 #ifdef DEBUG
diff --git a/content/canvas/src/WebGLContext.h b/content/canvas/src/WebGLContext.h
index 9309a6b55d42..3a71086be74b 100644
--- a/content/canvas/src/WebGLContext.h
+++ b/content/canvas/src/WebGLContext.h
@@ -80,6 +80,10 @@ class WebGLContextBoundObject;
 
 enum FakeBlackStatus { DoNotNeedFakeBlack, DoNeedFakeBlack, DontKnowIfNeedFakeBlack };
 
+struct VertexAttrib0Status {
+    enum { Default, EmulatedUninitializedArray, EmulatedInitializedArray };
+};
+
 struct WebGLTexelFormat {
     enum { Generic, Auto, RGBA8, RGB8, RGBX8, BGRA8, BGR8, BGRX8, RGBA5551, RGBA4444, RGB565, R8, RA8, A8 };
 };
@@ -371,6 +375,7 @@ public:
     // all context resources to be lost.
     PRUint32 Generation() { return mGeneration.value(); }
 
+protected:
     void SetDontKnowIfNeedFakeBlack() {
         mFakeBlackStatus = DontKnowIfNeedFakeBlack;
     }
@@ -379,11 +384,11 @@ public:
     void BindFakeBlackTextures();
     void UnbindFakeBlackTextures();
 
-    PRBool NeedFakeVertexAttrib0();
+    int WhatDoesVertexAttrib0Need();
     void DoFakeVertexAttrib0(WebGLuint vertexCount);
     void UndoFakeVertexAttrib0();
+    void InvalidateFakeVertexAttrib0();
 
-protected:
     nsCOMPtr<nsIDOMHTMLCanvasElement> mCanvasElement;
     nsHTMLCanvasElement *HTMLCanvasElement() {
         return static_cast<nsHTMLCanvasElement*>(mCanvasElement.get());
@@ -550,7 +555,10 @@ protected:
     PRBool mBlackTexturesAreInitialized;
 
     WebGLfloat mVertexAttrib0Vector[4];
-    nsAutoArrayPtr<WebGLfloat> mFakeVertexAttrib0Array;
+    WebGLfloat mFakeVertexAttrib0BufferObjectVector[4];
+    size_t mFakeVertexAttrib0BufferObjectSize;
+    GLuint mFakeVertexAttrib0BufferObject;
+    int mFakeVertexAttrib0BufferStatus;
 
     WebGLint mStencilRef;
     WebGLuint mStencilValueMask, mStencilWriteMask;
diff --git a/content/canvas/src/WebGLContextGL.cpp b/content/canvas/src/WebGLContextGL.cpp
index 130bde396163..9cae0aca9db7 100644
--- a/content/canvas/src/WebGLContextGL.cpp
+++ b/content/canvas/src/WebGLContextGL.cpp
@@ -1085,46 +1085,91 @@ WebGLContext::DisableVertexAttribArray(WebGLuint index)
     return NS_OK;
 }
 
-PRBool
-WebGLContext::NeedFakeVertexAttrib0()
+int
+WebGLContext::WhatDoesVertexAttrib0Need()
 {
-    return !gl->IsGLES2() &&
-           !mAttribBuffers[0].enabled;
+  // here we may assume that mCurrentProgram != null
+
+    // work around Mac OSX crash, see bug 631420
+#ifdef XP_MACOSX
+    if (mAttribBuffers[0].enabled &&
+        !mCurrentProgram->IsAttribInUse(0))
+        return VertexAttrib0Status::EmulatedUninitializedArray;
+#endif
+
+    return (gl->IsGLES2() || mAttribBuffers[0].enabled) ? VertexAttrib0Status::Default
+         : mCurrentProgram->IsAttribInUse(0)            ? VertexAttrib0Status::EmulatedInitializedArray
+                                                        : VertexAttrib0Status::EmulatedUninitializedArray;
 }
 
 void
 WebGLContext::DoFakeVertexAttrib0(WebGLuint vertexCount)
 {
-    if (!NeedFakeVertexAttrib0())
+    int whatDoesAttrib0Need = WhatDoesVertexAttrib0Need();
+
+    if (whatDoesAttrib0Need == VertexAttrib0Status::Default)
         return;
 
-    mFakeVertexAttrib0Array = new WebGLfloat[4 * vertexCount];
+    WebGLuint dataSize = sizeof(WebGLfloat) * 4 * vertexCount;
 
-    for(size_t i = 0; i < vertexCount; ++i) {
-        mFakeVertexAttrib0Array[4 * i + 0] = mVertexAttrib0Vector[0];
-        mFakeVertexAttrib0Array[4 * i + 1] = mVertexAttrib0Vector[1];
-        mFakeVertexAttrib0Array[4 * i + 2] = mVertexAttrib0Vector[2];
-        mFakeVertexAttrib0Array[4 * i + 3] = mVertexAttrib0Vector[3];
+    if (!mFakeVertexAttrib0BufferObject) {
+        gl->fGenBuffers(1, &mFakeVertexAttrib0BufferObject);
     }
 
-    gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, 0);
-    gl->fVertexAttribPointer(0, 4, LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0, mFakeVertexAttrib0Array);
+    // if the VBO status is already exactly what we need, or if the only difference is that it's initialized and
+    // we don't need it to be, then consider it OK
+    PRBool vertexAttrib0BufferStatusOK =
+        mFakeVertexAttrib0BufferStatus == whatDoesAttrib0Need ||
+        (mFakeVertexAttrib0BufferStatus == VertexAttrib0Status::EmulatedInitializedArray &&
+         whatDoesAttrib0Need == VertexAttrib0Status::EmulatedUninitializedArray);
+
+    if (!vertexAttrib0BufferStatusOK ||
+        mFakeVertexAttrib0BufferObjectSize < dataSize ||
+        mFakeVertexAttrib0BufferObjectVector[0] != mVertexAttrib0Vector[0] ||
+        mFakeVertexAttrib0BufferObjectVector[1] != mVertexAttrib0Vector[1] ||
+        mFakeVertexAttrib0BufferObjectVector[2] != mVertexAttrib0Vector[2] ||
+        mFakeVertexAttrib0BufferObjectVector[3] != mVertexAttrib0Vector[3])
+    {
+        mFakeVertexAttrib0BufferStatus = whatDoesAttrib0Need;
+        mFakeVertexAttrib0BufferObjectSize = dataSize;
+        mFakeVertexAttrib0BufferObjectVector[0] = mVertexAttrib0Vector[0];
+        mFakeVertexAttrib0BufferObjectVector[1] = mVertexAttrib0Vector[1];
+        mFakeVertexAttrib0BufferObjectVector[2] = mVertexAttrib0Vector[2];
+        mFakeVertexAttrib0BufferObjectVector[3] = mVertexAttrib0Vector[3];
+
+        gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mFakeVertexAttrib0BufferObject);
+
+        WebGLuint dataSize = sizeof(WebGLfloat) * 4 * vertexCount;
+
+        if (mFakeVertexAttrib0BufferStatus == VertexAttrib0Status::EmulatedInitializedArray) {
+            nsAutoArrayPtr<WebGLfloat> array(new WebGLfloat[4 * vertexCount]);
+            for(size_t i = 0; i < vertexCount; ++i) {
+                array[4 * i + 0] = mVertexAttrib0Vector[0];
+                array[4 * i + 1] = mVertexAttrib0Vector[1];
+                array[4 * i + 2] = mVertexAttrib0Vector[2];
+                array[4 * i + 3] = mVertexAttrib0Vector[3];
+            }
+            gl->fBufferData(LOCAL_GL_ARRAY_BUFFER, dataSize, array, LOCAL_GL_DYNAMIC_DRAW);
+        } else {
+            gl->fBufferData(LOCAL_GL_ARRAY_BUFFER, dataSize, nsnull, LOCAL_GL_DYNAMIC_DRAW);
+        }
+
+        gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mBoundArrayBuffer ? mBoundArrayBuffer->GLName() : 0);
+    }
+
+    gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mFakeVertexAttrib0BufferObject);
+    gl->fVertexAttribPointer(0, 4, LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0, 0);
 }
 
 void
 WebGLContext::UndoFakeVertexAttrib0()
 {
-    if (!NeedFakeVertexAttrib0())
+    int whatDoesAttrib0Need = WhatDoesVertexAttrib0Need();
+
+    if (whatDoesAttrib0Need == VertexAttrib0Status::Default)
         return;
 
-    mFakeVertexAttrib0Array = nsnull;
-
-    // first set the bound buffer as needed for subsequent gl->fVertexAttribPointer call.
-    // since in DoFakeVertexAttrib0() we called bindBuffer on buffer zero, we only need to do that if
-    // we have a nonzero buffer binding for this attrib.
-    if (mAttribBuffers[0].buf)
-        gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mAttribBuffers[0].buf->GLName());
-
+    gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mAttribBuffers[0].buf ? mAttribBuffers[0].buf->GLName() : 0);
     gl->fVertexAttribPointer(0,
                              mAttribBuffers[0].size,
                              mAttribBuffers[0].type,
@@ -1132,7 +1177,6 @@ WebGLContext::UndoFakeVertexAttrib0()
                              mAttribBuffers[0].stride,
                              (const GLvoid *) mAttribBuffers[0].byteOffset);
 
-    // now restore the bound buffer to its state before we did this whole draw call business
     gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mBoundArrayBuffer ? mBoundArrayBuffer->GLName() : 0);
 }