rebase

Author: ldetmer

gax-java/gax/src/main/java/com/google/api/gax/rpc/ClientContext.java

@@ -238,6 +238,10 @@ public static ClientContext create(StubSettings settings) throws IOException {
     if (credentials != null) {
       defaultCallContext = defaultCallContext.withCredentials(credentials);
     }
+    //TODO: if we decided to add setApiKey method need to check and throw exception if apikey and credentials are provided
+    if (settings.getApiKey() != null) {
+        defaultCallContext = defaultCallContext.withCredentials(ApiKeyCredentials.create(settings.getApiKey()));
+    }
     defaultCallContext = defaultCallContext.withEndpointContext(endpointContext);
 
     WatchdogProvider watchdogProvider = settings.getStreamWatchdogProvider();

gax-java/gax/src/main/java/com/google/api/gax/rpc/ClientSettings.java

@@ -109,6 +109,8 @@ public final String getQuotaProjectId() {
     return stubSettings.getQuotaProjectId();
   }
 
+  public final String getApiKey() {return stubSettings.getApiKey();}
+
   @Nullable
   public final WatchdogProvider getWatchdogProvider() {
     return stubSettings.getStreamWatchdogProvider();