Perform glReadPixels with PBOs in the gpu, if PBOs are available.

gpu/command_buffer/common/gles2_cmd_utils_implementation_autogen.h

Index: gpu/command_buffer/common/gles2_cmd_utils_implementation_autogen.h
diff --git a/gpu/command_buffer/common/gles2_cmd_utils_implementation_autogen.h b/gpu/command_buffer/common/gles2_cmd_utils_implementation_autogen.h
index 36975dd9774426f3d28c5b52f44a888dc0e64841..3c3fb33e2271158ac875bf7555972a47d7a8d447 100644
--- a/gpu/command_buffer/common/gles2_cmd_utils_implementation_autogen.h
+++ b/gpu/command_buffer/common/gles2_cmd_utils_implementation_autogen.h
@@ -86,6 +86,7 @@ static GLES2Util::EnumToString enum_to_string_table[] = {
   { 0x2601, "GL_LINEAR", },
   { 0x8C03, "GL_COMPRESSED_RGBA_PVRTC_2BPPV1_IMG", },
   { 0x9242, "GL_UNPACK_UNPREMULTIPLY_ALPHA_CHROMIUM", },
+  { 0x88BA, "GL_READ_WRITE", },
   { 0x88BB, "GL_BUFFER_ACCESS_OES", },
   { 0x88BC, "GL_BUFFER_MAPPED_OES", },
   { 0x88BD, "GL_BUFFER_MAP_POINTER_OES", },
@@ -227,7 +228,7 @@ static GLES2Util::EnumToString enum_to_string_table[] = {
   { 0x84F5, "GL_ASYNC_PIXEL_TRANSFERS_COMPLETED_CHROMIUM", },
   { 0x882A, "GL_DRAW_BUFFER5_NV", },
   { 0x80AA, "GL_SAMPLE_COVERAGE_VALUE", },
-  { 0x84F6, "GL_TEXTURE_BINDING_RECTANGLE_ARB", },
+  { 0x84F6, "GL_ASYNC_READ_PIXELS_COMPLETED_CHROMIUM", },
   { 0x80AB, "GL_SAMPLE_COVERAGE_INVERT", },
   { 0x8FC4, "GL_SHADER_BINARY_VIV", },
   { 0x882B, "GL_DRAW_BUFFER6_NV", },
@@ -1079,6 +1080,8 @@ std::string GLES2Util::GetStringQueryTarget(uint32 value) {
     { GL_LATENCY_QUERY_CHROMIUM, "GL_LATENCY_QUERY_CHROMIUM" },
     { GL_ASYNC_PIXEL_TRANSFERS_COMPLETED_CHROMIUM,
     "GL_ASYNC_PIXEL_TRANSFERS_COMPLETED_CHROMIUM" },
+    { GL_ASYNC_READ_PIXELS_COMPLETED_CHROMIUM,
+    "GL_ASYNC_READ_PIXELS_COMPLETED_CHROMIUM" },
   };
   return GLES2Util::GetQualifiedEnumString(
       string_table, arraysize(string_table), value);