Add tests for Android GL driver version extraction.

gpu/config/gpu_info_collector_android.cc

 // Copyright (c) 2012 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 "gpu/config/gpu_info_collector.h"
 
 #include "base/android/build_info.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_surface.h"
 
 namespace {
 
 std::string GetDriverVersionFromString(const std::string& version_string) {
-  // Extract driver version from the second number in a string like:
-  // "OpenGL ES 2.0 V@6.0 AU@ (CL@2946718)"
-
-  // Exclude first "2.0".
+  // We expect that android GL_VERSION strings will be of a form
+  // similar to: "OpenGL ES 2.0 V@6.0 AU@ (CL@2946718)" where the
+  // first match to [0-9][0-9.]* is the OpenGL ES version number, and
+  // the second match to [0-9][0-9.]* is the driver version (in this
+  // case, 6.0).
+  // It is currently assumed that the driver version has at least one
+  // period in it, and only the first two components are significant.
   size_t begin = version_string.find_first_of("0123456789");
   if (begin == std::string::npos)
     return "0";
   size_t end = version_string.find_first_not_of("01234567890.", begin);
 
   // Extract number of the form "%d.%d"
   begin = version_string.find_first_of("0123456789", end);
   if (begin == std::string::npos)
     return "0";
   end = version_string.find_first_not_of("01234567890.", begin);
@@ skipping 82 matching lines @@
   gpu_info->gpu.device_string = gpu_info->gl_renderer;
   return kCollectInfoSuccess;
 }
 
 void MergeGPUInfo(GPUInfo* basic_gpu_info,
                   const GPUInfo& context_gpu_info) {
   MergeGPUInfoGL(basic_gpu_info, context_gpu_info);
 }
 
 }  // namespace gpu