Bug 1384180 - Don't animate the stop->reload if the page loads within 150ms (too distracting). r=dao

MozReview-Commit-ID: 9KvMCRZo5LZ

--HG--
extra : rebase_source : b1392cf72d1cdc17fd3172b0fb48ddf7004a4bce

browser/base/content/browser.js

@@ -4865,6 +4865,9 @@ var XULBrowserWindow = {
   onUpdateCurrentBrowser: function XWB_onUpdateCurrentBrowser(aStateFlags, aStatus, aMessage, aTotalProgress) {
     if (FullZoom.updateBackgroundTabs)
       FullZoom.onLocationChange(gBrowser.currentURI, true);
+
+    CombinedStopReload.onTabSwitch();
+
     var nsIWebProgressListener = Components.interfaces.nsIWebProgressListener;
     var loadingDone = aStateFlags & nsIWebProgressListener.STATE_STOP;
     // use a pseudo-object instead of a (potentially nonexistent) channel for getting
@@ -4969,6 +4972,7 @@ var CombinedStopReload = {
     this.reload = reload;
     this.stop = stop;
     this.stopReloadContainer = this.reload.parentNode;
+    this.timeWhenSwitchedToStop = 0;
 
     // Disable animations until the browser has fully loaded.
     this.animate = false;
@@ -5036,13 +5040,26 @@ var CombinedStopReload = {
     });
   },
 
+  onTabSwitch() {
+    // Reset the time in the event of a tabswitch since the stored time
+    // would have been associated with the previous tab.
+    this.timeWhenSwitchedToStop = 0;
+  },
+
   switchToStop(aRequest, aWebProgress) {
     if (!this._initialized || !this._shouldSwitch(aRequest, aWebProgress)) {
       return;
     }
 
+    // Store the time that we switched to the stop button only if a request
+    // is active. Requests are null if the switch is related to a tabswitch.
+    // This is used to determine if we should show the stop->reload animation.
+    if (aRequest) {
+      this.timeWhenSwitchedToStop = window.performance.now();
+    }
+
     let shouldAnimate = AppConstants.MOZ_PHOTON_ANIMATIONS &&
-                        aRequest instanceof Ci.nsIRequest &&
+                        aRequest &&
                         aWebProgress.isTopLevel &&
                         aWebProgress.isLoadingDocument &&
                         !gBrowser.tabAnimationsInProgress &&
@@ -5065,10 +5082,11 @@ var CombinedStopReload = {
     }
 
     let shouldAnimate = AppConstants.MOZ_PHOTON_ANIMATIONS &&
-                        aRequest instanceof Ci.nsIRequest &&
+                        aRequest &&
                         aWebProgress.isTopLevel &&
                         !aWebProgress.isLoadingDocument &&
                         !gBrowser.tabAnimationsInProgress &&
+                        this._loadTimeExceedsMinimumForAnimation() &&
                         this.animate;
 
     if (shouldAnimate) {
@@ -5101,6 +5119,16 @@ var CombinedStopReload = {
     }, 650, this);
   },
 
+  _loadTimeExceedsMinimumForAnimation() {
+    // If the time between switching to the stop button then switching to
+    // the reload button exceeds 150ms, then we will show the animation.
+    // If we don't know when we switched to stop (a tabswitch occured while
+    // the page was loading), then we will not prevent the animation from
+    // occuring.
+    return !this.timeWhenSwitchedToStop ||
+           window.performance.now() - this.timeWhenSwitchedToStop > 150;
+  },
+
   _shouldSwitch(aRequest, aWebProgress) {
     if (aRequest &&
         aRequest.originalURI &&