Revert "Revert "Support class unloading in dex2oat for quicken multidex""

Bug: 63467744
Test: test-art-host

This reverts commit 6921d90a241f0307ac25120f8f976744d4a57706.

Change-Id: If70e31d3a15579dc75fd40bfef186e0124568c87
diff --git a/runtime/compiler_callbacks.h b/runtime/compiler_callbacks.h
index 806653a..c51bb5e 100644
--- a/runtime/compiler_callbacks.h
+++ b/runtime/compiler_callbacks.h
@@ -22,6 +22,8 @@
 
 namespace art {
 
+class CompilerDriver;
+
 namespace verifier {
 
 class MethodVerifier;
@@ -49,6 +51,13 @@
   virtual verifier::VerifierDeps* GetVerifierDeps() const = 0;
   virtual void SetVerifierDeps(verifier::VerifierDeps* deps ATTRIBUTE_UNUSED) {}
 
+  virtual bool CanAssumeVerified(ClassReference ref ATTRIBUTE_UNUSED) {
+    return false;
+  }
+
+  virtual void SetDoesClassUnloading(bool does_class_unloading ATTRIBUTE_UNUSED,
+                                     CompilerDriver* compiler_driver ATTRIBUTE_UNUSED) {}
+
   bool IsBootImage() {
     return mode_ == CallbackMode::kCompileBootImage;
   }