Fix ReadPixels implementation specific read format/type on desktop GL.

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 03f87167a04d297bb1826612e44f9736efba132d..57a1302496a4e60048aaf0645addfaee7c89c5ef 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -5066,7 +5066,7 @@ bool GLES2DecoderImpl::GetHelper(
             if (glGetError() == GL_NO_ERROR)
               return true;
           }
-          *params = GLES2Util::GetPreferredGLReadPixelsFormat(
+          *params = GLES2Util::GetGLReadPixelsImplementationFormat(
               GetBoundReadFrameBufferInternalFormat());
         }
         return true;
@@ -5080,7 +5080,7 @@ bool GLES2DecoderImpl::GetHelper(
             if (glGetError() == GL_NO_ERROR)
               return true;
           }
-          *params = GLES2Util::GetPreferredGLReadPixelsType(
+          *params = GLES2Util::GetGLReadPixelsImplementationType(
               GetBoundReadFrameBufferInternalFormat(),
               GetBoundReadFrameBufferTextureType());
         }
@@ -8752,9 +8752,6 @@ error::Error GLES2DecoderImpl::HandleReadPixels(uint32 immediate_data_size,
   std::vector<GLenum> accepted_formats;
   std::vector<GLenum> accepted_types;
   switch (src_internal_format) {
-    case GL_RGB10_A2UI:
-      accepted_formats.push_back(GL_RGBA);
-      accepted_types.push_back(GL_UNSIGNED_INT_2_10_10_10_REV);
     case GL_R8UI:
     case GL_R16UI:
     case GL_R32UI:
@@ -8763,6 +8760,7 @@ error::Error GLES2DecoderImpl::HandleReadPixels(uint32 immediate_data_size,
     case GL_RG32UI:
     // All the RGB_INTEGER formats are not renderable.
     case GL_RGBA8UI:
+    case GL_RGB10_A2UI:
     case GL_RGBA16UI:
     case GL_RGBA32UI:
       accepted_formats.push_back(GL_RGBA_INTEGER);
@@ -8780,6 +8778,13 @@ error::Error GLES2DecoderImpl::HandleReadPixels(uint32 immediate_data_size,
       accepted_formats.push_back(GL_RGBA_INTEGER);
       accepted_types.push_back(GL_INT);
       break;
+    case GL_RGB10_A2:
+      accepted_formats.push_back(GL_RGBA);
+      accepted_types.push_back(GL_UNSIGNED_BYTE);
+      // Special case with an extra supported format/type.
+      accepted_formats.push_back(GL_RGBA);
+      accepted_types.push_back(GL_UNSIGNED_INT_2_10_10_10_REV);
+      break;
     default:
       accepted_formats.push_back(GL_RGBA);
       {