Filter out redundant jumplist updates.

chrome/browser/jumplist_win.cc

Index: chrome/browser/jumplist_win.cc
diff --git a/chrome/browser/jumplist_win.cc b/chrome/browser/jumplist_win.cc
index f1e8a879b115547292fa55884733de91cb83c669..9f83cf981d04cd7f301494d4a93555079b503a18 100644
--- a/chrome/browser/jumplist_win.cc
+++ b/chrome/browser/jumplist_win.cc
@@ -46,6 +46,10 @@ using content::BrowserThread;
 
 namespace {
 
+// Delay jumplist update tasks to allow collapsing of redundant
+// update requests.

[gab, 2015/06/03 19:03:50]

Looks like "update" fits on previous line.

[brucedawson, 2015/06/04 17:11:59]

Done.

+const int kDelayForJumplistUpdateInMS = 3500;
+
 // Append the common switches to each shell link.
 void AppendCommonSwitches(ShellLinkItem* shell_link) {
   const char* kSwitchNames[] = { switches::kUserDataDir };
@@ -440,6 +444,21 @@ void JumpList::OnIncognitoAvailabilityChanged() {
 }
 
 void JumpList::PostRunUpdate() {
+

[gab, 2015/06/03 19:03:50]

No empty line.

[brucedawson, 2015/06/04 17:11:59]

Done.

+  // Initialize the one-shot timer to update the jumplists in a while.
+  // If there is already a request queued then cancel it and post the new
+  // request. This ensures that JumpListUpdates won't happen until there has
+  // been a brief quiet period, thus avoiding update storms.
+  if (timer_.IsRunning())

[gab, 2015/06/03 19:03:50]

{}s everywhere since the else's body is multiline.

[brucedawson, 2015/06/04 17:11:59]

Done.

+    timer_.Reset();
+  else
+    timer_.Start(FROM_HERE,
+                 base::TimeDelta::FromMilliseconds(kDelayForJumplistUpdateInMS),
+                 this,
+                 &JumpList::DeferredRunUpdate);
+}
+
+void JumpList::DeferredRunUpdate() {
   // Check if incognito windows (or normal windows) are disabled by policy.
   IncognitoModePrefs::Availability incognito_availability =
       profile_ ? IncognitoModePrefs::GetAvailability(profile_->GetPrefs())