Move getBufferSubDataAsync to an extension

third_party/WebKit/Source/modules/webgl/BUILD.gn

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//third_party/WebKit/Source/modules/modules.gni")
 
 blink_modules_sources("webgl") {
   sources = [
     "ANGLEInstancedArrays.cpp",
     "ANGLEInstancedArrays.h",
@@ skipping 64 matching lines @@
     "WebGLDepthTexture.h",
     "WebGLDrawBuffers.cpp",
     "WebGLDrawBuffers.h",
     "WebGLExtension.cpp",
     "WebGLExtension.h",
     "WebGLExtensionName.h",
     "WebGLFenceSync.cpp",
     "WebGLFenceSync.h",
     "WebGLFramebuffer.cpp",
     "WebGLFramebuffer.h",
+    "WebGLGetBufferSubDataAsync.cpp",
+    "WebGLGetBufferSubDataAsync.h",
     "WebGLLoseContext.cpp",
     "WebGLLoseContext.h",
     "WebGLObject.cpp",
     "WebGLObject.h",
     "WebGLProgram.cpp",
     "WebGLProgram.h",
     "WebGLQuery.cpp",
     "WebGLQuery.h",
     "WebGLRenderbuffer.cpp",
     "WebGLRenderbuffer.h",
@@ skipping 27 matching lines @@
     "WebGLVertexArrayObjectBase.h",
     "WebGLVertexArrayObjectOES.cpp",
     "WebGLVertexArrayObjectOES.h",
   ]
 
   # The modules/webgl/ directly is a larger module, and
   # the implementation depends on a fair chunk of core/ --
   # include the core pch for faster Windows compilation times.
   configs += [ "//third_party/WebKit/Source/core:blink_core_pch" ]
 }