Merge "Update keep rules for public api of r8"

src/main/java/com/android/tools/r8/ExtractMarker.java

diff --git a/src/main/java/com/android/tools/r8/ExtractMarker.java b/src/main/java/com/android/tools/r8/ExtractMarker.java
index 6fd04b6..fd85c25 100644
--- a/src/main/java/com/android/tools/r8/ExtractMarker.java
+++ b/src/main/java/com/android/tools/r8/ExtractMarker.java
@@ -26,6 +26,7 @@
 import java.util.Collection;
 import java.util.concurrent.ExecutionException;
 
+@Keep
 public class ExtractMarker {
   public static class VdexOrigin extends Origin {
 

src/main/java/com/android/tools/r8/GenerateMainDexList.java

diff --git a/src/main/java/com/android/tools/r8/GenerateMainDexList.java b/src/main/java/com/android/tools/r8/GenerateMainDexList.java
index 43989ff..6fe8ad0 100644
--- a/src/main/java/com/android/tools/r8/GenerateMainDexList.java
+++ b/src/main/java/com/android/tools/r8/GenerateMainDexList.java
@@ -28,6 +28,7 @@
 import java.util.concurrent.ExecutorService;
 import java.util.stream.Collectors;
 
+@Keep
 public class GenerateMainDexList {
   private final Timing timing = new Timing("maindex");
   private final InternalOptions options;