Suppress "errors" that aren't really errors.

remoting/webapp/client_session.js

Index: remoting/webapp/client_session.js
diff --git a/remoting/webapp/client_session.js b/remoting/webapp/client_session.js
index da8051e452e7e987b4efee4a77d271c2de0c6f40..f11f52d4162dc4d92126a2b848e708da5518b530 100644
--- a/remoting/webapp/client_session.js
+++ b/remoting/webapp/client_session.js
@@ -94,6 +94,13 @@ remoting.ClientSession = function(hostJid, hostPublicKey, sharedSecret,
   this.fullScreen_.addEventListener('click', this.callToggleFullScreen_, false);
   /** @type {number?} @private */
   this.bumpScrollTimer_ = null;
+  /**
+   * Allow error reporting to be suppressed in situations where it would not
+   * be useful, for example, when the device is offline.
+   *
+   * @type {boolean} @private
+   */
+  this.logErrors_ = true;

[Wez, 2012/08/07 00:01:00]

There's a danger that we suppress logging and miss something useful; we could
continue to log in these situations but include flags in the logged stanzas to
indicate e.g. whether the client thought it was online, etc, so that we get full
raw logging and can then post-process to get the numbers we need.

[Jamie, 2012/08/07 00:37:04]

We still log eof-session, and it will still have the error attached to it, but
we don't log it as an error any more. The data we would have logged prior to
this change is inferable if we're ever interested.

 };
 
 // Note that the positive values in both of these enums are copied directly
@@ -521,8 +528,15 @@ remoting.ClientSession.prototype.setState_ = function(newState) {
   if (this.onStateChange) {
     this.onStateChange(oldState, newState);
   }
-  this.logToServer.logClientSessionStateChange(this.state, this.error,
-      this.mode);
+  // If connection errors are being suppressed from the logs, translate
+  // FAILED to CLOSED here. This ensures that the duration is still logged.
+  var state = this.state;
+  if (this.state == remoting.ClientSession.State.FAILED &&
+      !this.logErrors_) {
+    console.log('Suppressing error.');
+    state = remoting.ClientSession.State.CLOSED;
+  }
+  this.logToServer.logClientSessionStateChange(state, this.error, this.mode);
 };
 
 /**
@@ -649,6 +663,17 @@ remoting.ClientSession.prototype.logStatistics = function(stats) {
 };
 
 /**
+ * Enable or disable logging of connection errors. For example, if attempting
+ * a connection using a cached JID, errors should not be logged because the
+ * JID will be refreshed and the connection retried.
+ *
+ * @param {boolean} enable True to log errors; false to suppress them.
+ */
+remoting.ClientSession.prototype.logErrors = function(enable) {
+  this.logErrors_ = enable;
+};
+
+/**
  * Toggles between full-screen and windowed mode.
  * @return {void} Nothing.
  * @private