[Reland] Fix ReadPixels from float fbo buffer in ES2/WebGL1.

ui/gl/gl_version_info.cc

Index: ui/gl/gl_version_info.cc
diff --git a/ui/gl/gl_version_info.cc b/ui/gl/gl_version_info.cc
index 42616509e54c99d30b44756a00f033d3c66c9f0b..3a10437f8614ba764f8d615f1f13f09650a404cc 100644
--- a/ui/gl/gl_version_info.cc
+++ b/ui/gl/gl_version_info.cc
@@ -43,11 +43,12 @@ GLVersionInfo::GLVersionInfo(const char* version_str, const char* renderer_str)
       is_angle(false),
       major_version(0),
       minor_version(0),
+      is_es2(false),
       is_es3(false),
       is_desktop_core_profile(false) {
   if (version_str) {
     ParseVersionString(version_str, &major_version, &minor_version,
-                       &is_es, &is_es3);
+                       &is_es, &is_es2, &is_es3);
   }
   if (renderer_str) {
     is_angle = base::StartsWith(renderer_str, "ANGLE",
@@ -59,11 +60,13 @@ void GLVersionInfo::ParseVersionString(const char* version_str,
                                        unsigned* major_version,
                                        unsigned* minor_version,
                                        bool* is_es,
+                                       bool* is_es2,
                                        bool* is_es3) {
   // Make sure the outputs are always initialized.
   *major_version = 0;
   *minor_version = 0;
   *is_es = false;
+  *is_es2 = false;
   *is_es3 = false;
   if (!version_str)
     return;
@@ -81,6 +84,8 @@ void GLVersionInfo::ParseVersionString(const char* version_str,
       *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);