Revert of Fix blits from multisampled renderbuffers to alpha:false WebGL back buffer.

gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc b/gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc
index 3600f809af1e651a59682c19bd055293b4d035ff..9bfcb6b2750c7578ba5e0b76107cdb2812d64803 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc
@@ -3485,15 +3485,22 @@ error::Error GLES2DecoderPassthroughImpl::DoBindUniformLocationCHROMIUM(
 error::Error GLES2DecoderPassthroughImpl::DoBindTexImage2DCHROMIUM(
     GLenum target,
     GLint imageId) {
-  return BindTexImage2DCHROMIUMImpl(target, 0, imageId);
-}
+  if (target != GL_TEXTURE_2D) {
+    InsertError(GL_INVALID_ENUM, "Invalid target");
+    return error::kNoError;
+  }
 
-error::Error
-GLES2DecoderPassthroughImpl::DoBindTexImage2DWithInternalformatCHROMIUM(
-    GLenum target,
-    GLenum internalformat,
-    GLint imageId) {
-  return BindTexImage2DCHROMIUMImpl(target, internalformat, imageId);
+  gl::GLImage* image = image_manager_->LookupImage(imageId);
+  if (image == nullptr) {
+    InsertError(GL_INVALID_OPERATION, "No image found with the given ID");
+    return error::kNoError;
+  }
+
+  if (!image->BindTexImage(target)) {
+    image->CopyTexImage(target);
+  }
+
+  return error::kNoError;
 }
 
 error::Error GLES2DecoderPassthroughImpl::DoReleaseTexImage2DCHROMIUM(