Revert "Replace javax ThreadSafe annotation with errorprone ThreadSafe (grpc#12742)"

This reverts commit ef35313 because it breaks Google internal build. Error Prone adds a lot of restrictions, which we may or may not want. We'd need to look at each case and decide what to do.

Author: kannanjgithub

api/src/main/java/io/grpc/Channel.java

@@ -16,7 +16,7 @@
 
 package io.grpc;
 
-import com.google.errorprone.annotations.ThreadSafe;
+import javax.annotation.concurrent.ThreadSafe;
 
 /**
  * A virtual connection to a conceptual endpoint, to perform RPCs. A channel is free to have zero or

api/src/main/java/io/grpc/ChannelLogger.java

@@ -16,7 +16,7 @@
 
 package io.grpc;
 
-import com.google.errorprone.annotations.ThreadSafe;
+import javax.annotation.concurrent.ThreadSafe;
 
 /**
  * A Channel-specific logger provided by GRPC library to {@link LoadBalancer} implementations.

api/src/main/java/io/grpc/ClientInterceptor.java

@@ -16,7 +16,7 @@
 
 package io.grpc;
 
-import com.google.errorprone.annotations.ThreadSafe;
+import javax.annotation.concurrent.ThreadSafe;
 
 /**
  * Interface for intercepting outgoing calls before they are dispatched by a {@link Channel}.

api/src/main/java/io/grpc/ClientStreamTracer.java

@@ -19,7 +19,7 @@
 import static com.google.common.base.Preconditions.checkNotNull;
 
 import com.google.common.base.MoreObjects;
-import com.google.errorprone.annotations.ThreadSafe;
+import javax.annotation.concurrent.ThreadSafe;
 
 /**
  * {@link StreamTracer} for the client-side.

api/src/main/java/io/grpc/CompressorRegistry.java

@@ -19,10 +19,10 @@
 import static com.google.common.base.Preconditions.checkArgument;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.errorprone.annotations.ThreadSafe;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import javax.annotation.Nullable;
+import javax.annotation.concurrent.ThreadSafe;
 
 /**
  * Encloses classes related to the compression and decompression of messages.

api/src/main/java/io/grpc/DecompressorRegistry.java

@@ -20,14 +20,14 @@
 import static com.google.common.base.Preconditions.checkNotNull;
 
 import com.google.common.base.Joiner;
-import com.google.errorprone.annotations.ThreadSafe;
 import java.nio.charset.Charset;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Set;
 import javax.annotation.Nullable;
+import javax.annotation.concurrent.ThreadSafe;
 
 /**
  * Encloses classes related to the compression and decompression of messages.

api/src/main/java/io/grpc/HandlerRegistry.java

@@ -16,10 +16,10 @@
 
 package io.grpc;
 
-import com.google.errorprone.annotations.ThreadSafe;
 import java.util.Collections;
 import java.util.List;
 import javax.annotation.Nullable;
+import javax.annotation.concurrent.ThreadSafe;
 
 /**
  * Registry of services and their methods used by servers to dispatching incoming calls.

api/src/main/java/io/grpc/LoadBalancer.java

@@ -22,7 +22,6 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 import com.google.common.base.Preconditions;
-import com.google.errorprone.annotations.ThreadSafe;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -33,6 +32,7 @@
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import javax.annotation.concurrent.NotThreadSafe;
+import javax.annotation.concurrent.ThreadSafe;
 
 /**
  * A pluggable component that receives resolved addresses from {@link NameResolver} and provides the
@@ -64,7 +64,7 @@
  * allows implementations to schedule tasks to be run in the same Synchronization Context, with or
  * without a delay, thus those tasks don't need to worry about synchronizing with the balancer
  * methods.
- *
+ * 
  * <p>However, the actual running thread may be the network thread, thus the following rules must be
  * followed to prevent blocking or even dead-locking in a network:
  *
@@ -417,7 +417,7 @@ public void handleSubchannelState(
    *
    * <p>This method should always return a constant value.  It's not specified when this will be
    * called.
-   *
+   * 
    * <p>Note that this method is only called when implementing {@code handleResolvedAddresses()}
    * instead of {@code acceptResolvedAddresses()}.
    *
@@ -640,7 +640,7 @@ private PickResult(
      *                            stream is created at all in some cases.
      * @since 1.3.0
      */
-    // TODO(shivaspeaks): Need to deprecate old APIs and create new ones,
+    // TODO(shivaspeaks): Need to deprecate old APIs and create new ones, 
     // per https://github.com/grpc/grpc-java/issues/12662.
     public static PickResult withSubchannel(
         Subchannel subchannel, @Nullable ClientStreamTracer.Factory streamTracerFactory) {
@@ -1332,7 +1332,7 @@ public MetricRecorder getMetricRecorder() {
   }
 
   /**
-   * A logical connection to a server, or a group of equivalent servers represented by an {@link
+   * A logical connection to a server, or a group of equivalent servers represented by an {@link 
    * EquivalentAddressGroup}.
    *
    * <p>It maintains at most one physical connection (aka transport) for sending new RPCs, while

api/src/main/java/io/grpc/LoadBalancerRegistry.java

@@ -20,7 +20,6 @@
 import static com.google.common.base.Preconditions.checkNotNull;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.errorprone.annotations.ThreadSafe;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.LinkedHashMap;
@@ -31,6 +30,7 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import javax.annotation.Nullable;
+import javax.annotation.concurrent.ThreadSafe;
 
 /**
  * Registry of {@link LoadBalancerProvider}s.  The {@link #getDefaultRegistry default instance}

api/src/main/java/io/grpc/ManagedChannel.java

@@ -16,8 +16,8 @@
 
 package io.grpc;
 
-import com.google.errorprone.annotations.ThreadSafe;
 import java.util.concurrent.TimeUnit;
+import javax.annotation.concurrent.ThreadSafe;
 
 /**
  * A {@link Channel} that provides lifecycle management.