Make WebGLRenderingContext.getAttachedShaders() return type nullable

Source/core/html/canvas/WebGLRenderingContextBase.cpp

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 2009 matching lines @@
 PassRefPtr<WebGLActiveInfo> WebGLRenderingContextBase::getActiveUniform(WebGLProgram* program, GLuint index)
 {
     if (isContextLost() || !validateWebGLObject("getActiveUniform", program))
         return nullptr;
     blink::WebGraphicsContext3D::ActiveInfo info;
     if (!webContext()->getActiveUniform(objectOrZero(program), index, info))
         return nullptr;
     return WebGLActiveInfo::create(info.name, info.type, info.size);
 }
 
-bool WebGLRenderingContextBase::getAttachedShaders(WebGLProgram* program, Vector<RefPtr<WebGLShader> >& shaderObjects)
+Nullable<Vector<RefPtr<WebGLShader> > > WebGLRenderingContextBase::getAttachedShaders(WebGLProgram* program)
 {
-    shaderObjects.clear();
     if (isContextLost() || !validateWebGLObject("getAttachedShaders", program))
-        return false;
+        return Nullable<Vector<RefPtr<WebGLShader> > >();
 
+    Vector<RefPtr<WebGLShader> > shaderObjects;
     const GLenum shaderType[] = {
         GL_VERTEX_SHADER,
         GL_FRAGMENT_SHADER
     };
     for (unsigned i = 0; i < sizeof(shaderType) / sizeof(GLenum); ++i) {
         WebGLShader* shader = program->getAttachedShader(shaderType[i]);
         if (shader)
             shaderObjects.append(shader);
     }
-    return true;
+    return shaderObjects;
 }
 
 GLint WebGLRenderingContextBase::getAttribLocation(WebGLProgram* program, const String& name)
 {
     if (isContextLost() || !validateWebGLObject("getAttribLocation", program))
         return -1;
     if (!validateLocationLength("getAttribLocation", name))
         return -1;
     if (!validateString("getAttribLocation", name))
         return -1;
@@ skipping 3639 matching lines @@
         if (m_textureUnits[i].m_texture2DBinding
             || m_textureUnits[i].m_textureCubeMapBinding) {
             m_onePlusMaxNonDefaultTextureUnit = i + 1;
             return;
         }
     }
     m_onePlusMaxNonDefaultTextureUnit = 0;
 }
 
 } // namespace WebCore