Remove SpawnStrategy#beginExecution().

The corresponding method on TestStrategy and the like still remains (for the
time being)

RELNOTES: None.
PiperOrigin-RevId: 491304646
Change-Id: I263aa92af324ce17109163a5145cd32bb88c7486

src/main/java/com/google/devtools/build/lib/actions/SpawnStrategy.java

@@ -37,19 +37,6 @@ public interface SpawnStrategy {
   ImmutableList<SpawnResult> exec(Spawn spawn, ActionExecutionContext actionExecutionContext)
       throws ExecException, InterruptedException;
 
-  /**
-   * Executes the given spawn, possibly asynchronously, and returns a SpawnContinuation to represent
-   * the execution. Otherwise all requirements from {@link #exec} apply.
-   */
-  default SpawnContinuation beginExecution(
-      Spawn spawn, ActionExecutionContext actionExecutionContext) throws InterruptedException {
-    try {
-      return SpawnContinuation.immediate(exec(spawn, actionExecutionContext));
-    } catch (ExecException e) {
-      return SpawnContinuation.failedWithExecException(e);
-    }
-  }
-
   /**
    * Returns whether this SpawnActionContext supports executing the given Spawn. This does not allow
    * using the legacy fallback to local execution controlled by the {@code

src/main/java/com/google/devtools/build/lib/exec/SpawnStrategyResolver.java

@@ -19,7 +19,6 @@
 import com.google.devtools.build.lib.actions.ActionExecutionContext;
 import com.google.devtools.build.lib.actions.ExecException;
 import com.google.devtools.build.lib.actions.Spawn;
-import com.google.devtools.build.lib.actions.SpawnContinuation;
 import com.google.devtools.build.lib.actions.SpawnResult;
 import com.google.devtools.build.lib.actions.SpawnStrategy;
 import com.google.devtools.build.lib.actions.UserExecException;
@@ -46,24 +45,6 @@ public ImmutableList<SpawnResult> exec(Spawn spawn, ActionExecutionContext actio
     return resolveOne(spawn, actionExecutionContext).exec(spawn, actionExecutionContext);
   }
 
-  /**
-   * Queues execution of the given spawn with the {@linkplain SpawnStrategyRegistry highest priority
-   * strategy} that can be found for it.
-   *
-   * @param actionExecutionContext context in which to execute the spawn
-   * @return handle to the spawn's pending execution (or failure thereof)
-   */
-  public SpawnContinuation beginExecution(
-      Spawn spawn, ActionExecutionContext actionExecutionContext) throws InterruptedException {
-    SpawnStrategy resolvedStrategy;
-    try {
-      resolvedStrategy = resolveOne(spawn, actionExecutionContext);
-    } catch (ExecException e) {
-      return SpawnContinuation.failedWithExecException(e);
-    }
-    return resolvedStrategy.beginExecution(spawn, actionExecutionContext);
-  }
-
   private SpawnStrategy resolveOne(Spawn spawn, ActionExecutionContext actionExecutionContext)
       throws UserExecException {
     List<? extends SpawnStrategy> strategies = resolve(spawn, actionExecutionContext);