Add @GoogleInternal propagateCancellation to Futures.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=169256636

android/guava/src/com/google/common/util/concurrent/AbstractCatchingFuture.java

@@ -164,7 +164,7 @@ protected String pendingToString() {
 
   @Override
   protected final void afterDone() {
-    maybePropagateCancellation(inputFuture);
+    maybePropagateCancellationTo(inputFuture);
     this.inputFuture = null;
     this.exceptionType = null;
     this.fallback = null;

android/guava/src/com/google/common/util/concurrent/AbstractFuture.java

@@ -890,11 +890,8 @@ final Throwable trustedGetException() {
   /**
    * If this future has been cancelled (and possibly interrupted), cancels (and possibly interrupts)
    * the given future (if available).
-   *
-   * <p>This method should be used only when this future is completed. It is designed to be called
-   * from {@code done}.
    */
-  final void maybePropagateCancellation(@Nullable Future<?> related) {
+  final void maybePropagateCancellationTo(@Nullable Future<?> related) {
     if (related != null & isCancelled()) {
       related.cancel(wasInterrupted());
     }

android/guava/src/com/google/common/util/concurrent/AbstractTransformFuture.java

@@ -188,7 +188,7 @@ public final void run() {
 
   @Override
   protected final void afterDone() {
-    maybePropagateCancellation(inputFuture);
+    maybePropagateCancellationTo(inputFuture);
     this.inputFuture = null;
     this.function = null;
   }

android/guava/src/com/google/common/util/concurrent/Futures.java

@@ -1586,6 +1586,33 @@ private static void wrapAndThrowUnchecked(Throwable cause) {
    * Fork-Join framework: http://docs.oracle.com/javase/tutorial/essential/concurrency/forkjoin.html
    */
 
+  private static void maybePropagateCancellation(
+      @Nullable ListenableFuture<?> from, @Nullable Future<?> to) {
+    // AbstractFuture can propagate the mayInterruptIfRunning bit.
+    if (from instanceof AbstractFuture) {
+      ((AbstractFuture<?>) from).maybePropagateCancellationTo(to);
+    } else if (from != null && from.isCancelled() && to != null) {
+      to.cancel(false);
+    }
+  }
+
+  private static final class CancellationPropagater implements Runnable {
+    ListenableFuture<?> from;
+    Future<?> to;
+
+    CancellationPropagater(ListenableFuture<?> from, Future<?> to) {
+      this.from = from;
+      this.to = to;
+    }
+
+    @Override
+    public void run() {
+      maybePropagateCancellation(from, to);
+      from = null;
+      to = null;
+    }
+  }
+
   /**
    * A checked future that uses a function to map from exceptions to the appropriate checked type.
    */

android/guava/src/com/google/common/util/concurrent/TimeoutFuture.java

@@ -136,7 +136,7 @@ protected String pendingToString() {
 
   @Override
   protected void afterDone() {
-    maybePropagateCancellation(delegateRef);
+    maybePropagateCancellationTo(delegateRef);
 
     Future<?> localTimer = timer;
     // Try to cancel the timer as an optimization.

guava-gwt/src-super/com/google/common/util/concurrent/super/com/google/common/util/concurrent/AbstractFuture.java

@@ -155,7 +155,7 @@ protected boolean setFuture(ListenableFuture<? extends V> future) {
 
     // If this future is already cancelled, cancel the delegate.
     // TODO(cpovirk): Should we do this at the end of the method, as in the server version?
-    // TODO(cpovirk): Use maybePropagateCancellation?
+    // TODO(cpovirk): Use maybePropagateCancellationTo?
     if (isCancelled()) {
       future.cancel(mayInterruptIfRunning);
     }
@@ -192,7 +192,7 @@ final Throwable trustedGetException() {
     return throwable;
   }
 
-  final void maybePropagateCancellation(@Nullable Future<?> related) {
+  final void maybePropagateCancellationTo(@Nullable Future<?> related) {
     if (related != null & isCancelled()) {
       related.cancel(wasInterrupted());
     }

guava/src/com/google/common/util/concurrent/AbstractCatchingFuture.java

@@ -164,7 +164,7 @@ protected String pendingToString() {
 
   @Override
   protected final void afterDone() {
-    maybePropagateCancellation(inputFuture);
+    maybePropagateCancellationTo(inputFuture);
     this.inputFuture = null;
     this.exceptionType = null;
     this.fallback = null;

guava/src/com/google/common/util/concurrent/AbstractFuture.java

@@ -890,11 +890,8 @@ final Throwable trustedGetException() {
   /**
    * If this future has been cancelled (and possibly interrupted), cancels (and possibly interrupts)
    * the given future (if available).
-   *
-   * <p>This method should be used only when this future is completed. It is designed to be called
-   * from {@code done}.
    */
-  final void maybePropagateCancellation(@Nullable Future<?> related) {
+  final void maybePropagateCancellationTo(@Nullable Future<?> related) {
     if (related != null & isCancelled()) {
       related.cancel(wasInterrupted());
     }

guava/src/com/google/common/util/concurrent/AbstractTransformFuture.java

@@ -188,7 +188,7 @@ public final void run() {
 
   @Override
   protected final void afterDone() {
-    maybePropagateCancellation(inputFuture);
+    maybePropagateCancellationTo(inputFuture);
     this.inputFuture = null;
     this.function = null;
   }

guava/src/com/google/common/util/concurrent/Futures.java

@@ -1586,6 +1586,33 @@ private static void wrapAndThrowUnchecked(Throwable cause) {
    * Fork-Join framework: http://docs.oracle.com/javase/tutorial/essential/concurrency/forkjoin.html
    */
 
+  private static void maybePropagateCancellation(
+      @Nullable ListenableFuture<?> from, @Nullable Future<?> to) {
+    // AbstractFuture can propagate the mayInterruptIfRunning bit.
+    if (from instanceof AbstractFuture) {
+      ((AbstractFuture<?>) from).maybePropagateCancellationTo(to);
+    } else if (from != null && from.isCancelled() && to != null) {
+      to.cancel(false);
+    }
+  }
+
+  private static final class CancellationPropagater implements Runnable {
+    ListenableFuture<?> from;
+    Future<?> to;
+
+    CancellationPropagater(ListenableFuture<?> from, Future<?> to) {
+      this.from = from;
+      this.to = to;
+    }
+
+    @Override
+    public void run() {
+      maybePropagateCancellation(from, to);
+      from = null;
+      to = null;
+    }
+  }
+
   /**
    * A checked future that uses a function to map from exceptions to the appropriate checked type.
    */

guava/src/com/google/common/util/concurrent/TimeoutFuture.java

@@ -136,7 +136,7 @@ protected String pendingToString() {
 
   @Override
   protected void afterDone() {
-    maybePropagateCancellation(delegateRef);
+    maybePropagateCancellationTo(delegateRef);
 
     Future<?> localTimer = timer;
     // Try to cancel the timer as an optimization.