Add options to ResourceShrinkerAction to generate an updated R.txt.

--
MOS_MIGRATED_REVID=134312343

src/tools/android/java/com/google/devtools/build/android/ResourceShrinkerAction.java

@@ -21,6 +21,7 @@
 import com.google.devtools.build.android.Converters.ExistingPathConverter;
 import com.google.devtools.build.android.Converters.PathConverter;
 import com.google.devtools.build.android.Converters.PathListConverter;
+import com.google.devtools.build.android.Converters.VariantConfigurationTypeConverter;
 import com.google.devtools.common.options.Converters.CommaSeparatedOptionListConverter;
 import com.google.devtools.common.options.Option;
 import com.google.devtools.common.options.OptionsBase;
@@ -137,12 +138,27 @@ public static final class Options extends OptionsBase {
         help = "Path to where the shrunk resource.ap_ should be written.")
     public Path shrunkResources;
 
+    @Option(name = "rTxtOutput",
+        defaultValue = "null",
+        converter = PathConverter.class,
+        category = "output",
+        help = "Path to where the R.txt should be written.")
+    public Path rTxtOutput;
+
     @Option(name = "log",
         defaultValue = "null",
         category = "output",
         converter = PathConverter.class,
         help = "Path to where the shrinker log should be written.")
     public Path log;
+
+    @Option(name = "packageType",
+        defaultValue = "DEFAULT",
+        converter = VariantConfigurationTypeConverter.class,
+        category = "config",
+        help = "Variant configuration type for packaging the resources."
+            + " Acceptible values DEFAULT, LIBRARY, TEST")
+    public VariantConfiguration.Type packageType;
   }
 
   private static AaptConfigOptions aaptConfigOptions;
@@ -216,6 +232,11 @@ public static void main(String[] args) throws Exception {
       logger.fine(String.format("Shrinking resources finished at %sms",
           timer.elapsed(TimeUnit.MILLISECONDS)));
 
+      Path generatedSources = null;
+      if (options.rTxtOutput != null) {
+        generatedSources = working.resolve("generated_resources");
+      }
+
       // Build ap_ with shrunk resources.
       resourceProcessor.processResources(
           aaptConfigOptions.aapt,
@@ -230,7 +251,7 @@ public static void main(String[] args) throws Exception {
           new MergedAndroidData(
               shrunkResources, resourceFiles.resolve("assets"), options.primaryManifest),
           ImmutableList.<DependencyAndroidData>of() /* libraries */,
-          null /* sourceOutputDir */,
+          generatedSources,
           options.shrunkApk,
           null /* proguardOutput */,
           null /* mainDexProguardOutput */,
@@ -240,6 +261,12 @@ public static void main(String[] args) throws Exception {
         resourceProcessor.createResourcesZip(shrunkResources, resourceFiles.resolve("assets"),
             options.shrunkResources, false /* compress */);
       }
+      if (options.rTxtOutput != null) {
+        resourceProcessor.copyRToOutput(
+            generatedSources,
+            options.rTxtOutput,
+            options.packageType == VariantConfiguration.Type.LIBRARY);
+      }
       logger.fine(String.format("Packing resources finished at %sms",
           timer.elapsed(TimeUnit.MILLISECONDS)));
     } catch (Exception e) {