Fix the crash of compressedTexImage3D for the WebGL2 conformance test page.

third_party/WebKit/Source/modules/webgl/WebGLTexture.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 268 matching lines @@
 }
 
 bool WebGLTexture::isValid(GLenum target, GLint level) const
 {
     const LevelInfo* info = getLevelInfo(target, level);
     if (!info)
         return 0;
     return info->valid;
 }
 
+bool WebGLTexture::isValidLevel(GLenum target, GLint level) const
+{
+    if (!object() || !m_target)
+        return false;
+    int targetIndex = mapTargetToIndex(target);
+    if (targetIndex < 0 || targetIndex >= static_cast<int>(m_info.size()))
+        return false;
+    if (level < 0 || level >= static_cast<GLint>(m_info[targetIndex].size()))
+        return false;
+    return true;
+}
+
 bool WebGLTexture::isNPOT(GLsizei width, GLsizei height)
 {
     ASSERT(width >= 0 && height >= 0);
     if (!width || !height)
         return false;
     if ((width & (width - 1)) || (height & (height - 1)))
         return true;
     return false;
 }
 
@@ skipping 295 matching lines @@
     case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
     case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
     case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
         return GL_UNSIGNED_BYTE;
     default:
         return GL_NONE;
     }
 }
 
 } // namespace blink