Update HIDL-related documentation.

This is a followup CL to previous @SystemApi CLs.

Bug: N/A
Test: N/A
Change-Id: I9c7dcc776dcfb89fd90afa4fc5d74e40ff0a5f94
Merged-In: I9c7dcc776dcfb89fd90afa4fc5d74e40ff0a5f94
(cherry picked from commit 739811a5c5)

core/java/android/os/HwBinder.java

@@ -87,6 +87,9 @@ public abstract class HwBinder implements IHwBinder {
      * Configures how many threads the process-wide hwbinder threadpool
      * has to process incoming requests.
      *
+     * @param maxThreads total number of threads to create (includes this thread if
+     *     callerWillJoin is true)
+     * @param callerWillJoin whether joinRpcThreadpool will be called in advance
      * @hide
      */
     @SystemApi
@@ -125,6 +128,12 @@ public abstract class HwBinder implements IHwBinder {
 
     /**
      * Enable instrumentation if available.
+     *
+     * On a non-user build, this method:
+     * - tries to enable atracing (if enabled)
+     * - tries to enable coverage dumps (if running in VTS)
+     * - tries to enable record and replay (if running in VTS)
+     *
      * @hide
      */
     @SystemApi

core/java/android/os/IHwBinder.java

@@ -30,6 +30,11 @@ public interface IHwBinder {
     /**
      * Process a hwbinder transaction.
      *
+     * @param code interface specific code for interface.
+     * @param request parceled transaction
+     * @param reply object to parcel reply into
+     * @param flags transaction flags to be chosen by wire protocol
+     *
      * @hide
      */
     @SystemApi
@@ -39,6 +44,7 @@ public interface IHwBinder {
 
     /**
      * Return as IHwInterface instance only if this implements descriptor.
+     *
      * @param descriptor for example foo.bar@1.0::IBaz
      * @hide
      */
@@ -53,6 +59,8 @@ public interface IHwBinder {
     public interface DeathRecipient {
         /**
          * Callback for a registered process dying.
+         *
+         * @param cookie cookie this death recipient was registered with.
          */
         @SystemApi
         public void serviceDied(long cookie);
@@ -61,11 +69,16 @@ public interface IHwBinder {
     /**
      * Notifies the death recipient with the cookie when the process containing
      * this binder dies.
+     *
+     * @param recipient callback object to be called on object death.
+     * @param cookie value to be given to callback on object death.
      */
     @SystemApi
     public boolean linkToDeath(DeathRecipient recipient, long cookie);
     /**
      * Unregisters the death recipient from this binder.
+     *
+     * @param recipient callback to no longer recieve death notifications on this binder.
      */
     @SystemApi
     public boolean unlinkToDeath(DeathRecipient recipient);

core/java/android/os/IHwInterface.java

@@ -21,7 +21,7 @@ import android.annotation.SystemApi;
 @SystemApi
 public interface IHwInterface {
     /**
-     * Returns the binder object that corresponds to an interface.
+     * @return the binder object that corresponds to this interface.
      */
     @SystemApi
     public IHwBinder asBinder();