Update data reduction proxy statistics prefs less often on desktop

chrome/test/data/webui/net_internals/bandwidth_view.js

Index: chrome/test/data/webui/net_internals/bandwidth_view.js
diff --git a/chrome/test/data/webui/net_internals/bandwidth_view.js b/chrome/test/data/webui/net_internals/bandwidth_view.js
index 5bbef70a992fee75d01a10307c8821a69b136e37..8e854491a275b1e2c87e56784ed807e165e0cb32 100644
--- a/chrome/test/data/webui/net_internals/bandwidth_view.js
+++ b/chrome/test/data/webui/net_internals/bandwidth_view.js
@@ -42,7 +42,7 @@ BandwidthTask.prototype = {
     assertEquals('string', typeof url);
     this.url_ = url;
     g_browser.addSessionNetworkStatsObserver(this, true);
-    g_browser.addHistoricNetworkStatsObserver(this, true);
+    g_browser.addHistoricNetworkStatsObserver(this, false);

[mmenke, 2014/09/18 14:54:46]

Hrm...Really not sure why this is needed - we should send data to new observers
even if it hasn't changed...  Not going to block this CL on the issue, or
require you guys to investigate...but it's strange we need to do it.

     NetInternalsTest.switchToView('bandwidth');
     chrome.send('loadPage', [this.url_]);
   },
@@ -120,15 +120,16 @@ BandwidthTask.prototype = {
    * @param {object} networkStats State of the network session.
    */
   onHistoricNetworkStatsChanged: function(networkStats) {
-    if (this.isDone())
+    if (this.isDone() || this.historicVerified)

[mmenke, 2014/09/18 14:54:46]

nit:  May as well "|| this.sessionVerified" to the onSessionNetworkStatsChanged
call as well - not sure if either is needed, but I think it's better to be
consistent.

       return;
-    // Wait until the received content length is at least the size of
-    // our test page and favicon.
-    var expectedLength = this.expectedLength_ + this.faviconLength_;
-    if (networkStats.historic_received_content_length >= expectedLength) {
+    console.log("checking network stats");

[mmenke, 2014/09/18 14:54:46]

nit:  Remove logging.

+    // The received content length should be zero since the historic
+    // information only updates every hour.
+    var expectedLength = 0;
+    // Wait until the table has changed, otherwise the columns will be NaN
+    if (!isNaN(this.getBandwidthTableCell_(0, 2))) {
       expectLE(expectedLength, networkStats.historic_original_content_length);
-      // Column 2 contains historic information, and it should be the same as
-      // the session information, because previously there was no history.
+      // Column 2 contains historic information.
       this.validateBandwidthTableColumn_(2, expectedLength, expectedLength);
       this.historicVerified = true;
       this.completeIfDone();