Generate INVALID_OPERATION if feedback loops exist in CopyTex{Sub}Image2D.

gpu/command_buffer/service/gles2_cmd_decoder_unittest_framebuffers.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder_unittest_framebuffers.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder_unittest_framebuffers.cc b/gpu/command_buffer/service/gles2_cmd_decoder_unittest_framebuffers.cc
index 32ba98dfd56b6367f09cb1521318b2f8c676b617..ce8f3071a480e56f6df0a4347f49f55c29cb84d5 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder_unittest_framebuffers.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder_unittest_framebuffers.cc
@@ -2022,7 +2022,15 @@ void GLES2DecoderWithShaderTest::CheckTextureChangesMarkFBOAsNotComplete(
       .RetiresOnSaturation();
   CopyTexImage2D cmd;
   cmd.Init(GL_TEXTURE_2D, 0, GL_RGB, 0, 0, 1, 1);
+  // Unbind fbo and bind again after CopyTexImage2D tp avoid feedback loops.
+  if (bound_fbo) {
+    DoBindFramebuffer(GL_FRAMEBUFFER, 0, 0);
+  }
   EXPECT_EQ(error::kNoError, ExecuteCmd(cmd));
+  if (bound_fbo) {
+    DoBindFramebuffer(
+        GL_FRAMEBUFFER, client_framebuffer_id_, kServiceFramebufferId);
+  }
   EXPECT_FALSE(framebuffer_manager->IsComplete(framebuffer));
 
   // Test deleting texture marks fbo as not complete.