Revert of Suppress findbugs warnings on Chromium for syncronized methods

customtabs/src/android/support/customtabs/CustomTabsCallback.java

Index: customtabs/src/android/support/customtabs/CustomTabsCallback.java
diff --git a/customtabs/src/android/support/customtabs/CustomTabsCallback.java b/customtabs/src/android/support/customtabs/CustomTabsCallback.java
index 0f3f40ac626e20e5d34cf938b793b907d7d3df7b..261fc870e30196ca2c9036eea9886210d359b04e 100644
--- a/customtabs/src/android/support/customtabs/CustomTabsCallback.java
+++ b/customtabs/src/android/support/customtabs/CustomTabsCallback.java
@@ -18,8 +18,6 @@
 
 import android.net.Uri;
 import android.os.Bundle;
-
-import org.chromium.base.annotations.SuppressFBWarnings;
 
 /**
  * A callback class for custom tabs client to get messages regarding events in their custom tabs. In
@@ -73,7 +71,6 @@
      *               from this {@link CustomTabsSession}.
      * @param extras Reserved for future use.
      */
-    @SuppressFBWarnings("CHROMIUM_SYNCHRONIZED_METHOD")
     public synchronized void onMessageChannelReady(Uri origin, Bundle extras) {}
 
     /**
@@ -85,7 +82,6 @@
      * @param message The message sent.
      * @param extras Reserved for future use.
      */
-    @SuppressFBWarnings("CHROMIUM_SYNCHRONIZED_METHOD")
     public synchronized void onPostMessage(String message, Bundle extras) {}
 
     /**