Parse GL_VERSION incorrectly when version string is without release_number

ui/gl/gl_version_info.cc

 // Copyright 2014 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.
 
 #include "ui/gl/gl_version_info.h"
 
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_tokenizer.h"
 #include "base/strings/string_util.h"
 
@@ skipping 54 matching lines @@
   *major_version = 0;
   *minor_version = 0;
   *is_es = false;
   *is_es2 = false;
   *is_es3 = false;
   if (!version_str)
     return;
   std::string lstr(base::ToLowerASCII(version_str));
   *is_es = (lstr.length() > 12) && (lstr.substr(0, 9) == "opengl es");
   if (*is_es)
     lstr = lstr.substr(10, 3);

[xinghua.cao, 2016/06/16 10:29:05]

If OpenGL version string is without release number, take mesa for example, its
verstion string is:
4.3 (Core Profile) Mesa 11.2.0
The code will parse the major and minor version is:
major: 4, minor: 0
It is not correct, so take " " as a separator.
Version string is legal without release number. The version number uses one of
these forms:
major_number.minor_number major_number.minor_number.release_number
the reference link is https://www.opengl.org/sdk/docs/man2/xhtml/glGetString.xml

[Ken Russell (switch to Gerrit), 2016/06/16 20:12:22]

Thanks for tracking this down.

Could you please create a new file in this directory,
gl_version_info_unittest.cc, and add a couple of tests for this code? Please try
parsing a few representative GL_VERSION strings like:

OpenGL ES 2.0 (ANGLE 2.1.0.cd1b12260360)
2.1 INTEL-10.6.33
4.5.0 NVIDIA 364.19
4.3 (Core Profile) Mesa 11.2.0

(these were taken from a few tests' logs on
https://build.chromium.org/p/chromium.gpu.fyi/console )

The new test can be added to the gl_unittests target in src/ui/gl/BUILD.gn and
src/ui/gl/gl_tests.gyp .

Thanks.

-  base::StringTokenizer tokenizer(lstr.begin(), lstr.end(), ".");
+  base::StringTokenizer tokenizer(lstr.begin(), lstr.end(), ". ");
   unsigned major, minor;
   if (tokenizer.GetNext() &&
       base::StringToUint(tokenizer.token_piece(), &major)) {
     *major_version = major;
     if (tokenizer.GetNext() &&
         base::StringToUint(tokenizer.token_piece(), &minor)) {
       *minor_version = minor;
     }
   }
   if (*is_es && *major_version == 2)
     *is_es2 = true;
   if (*is_es && *major_version == 3)
     *is_es3 = true;
   DCHECK(major_version != 0);
 }
 
 }  // namespace gl