this addresses 44f1a61c42 (commitcomment-11015041)

src/js/contentscript-end.js

@@ -153,24 +153,6 @@ var collapser = (function() {
     var newRequests = [];
     var pendingRequests = {};
     var pendingRequestCount = 0;
-    var backgroundImage = [
-        'linear-gradient(',
-            '0deg,',
-            'rgba(0,0,0,0.02) 25%,',
-            'rgba(0,0,0,0.05) 25%,',
-            'rgba(0,0,0,0.05) 75%,',
-            'rgba(0,0,0,0.02) 75%,',
-            'rgba(0,0,0,0.02)',
-        ') center center / 10px 10px repeat scroll,',
-        'linear-gradient(',
-            '90deg,',
-            'rgba(0,0,0,0.02) 25%,',
-            'rgba(0,0,0,0.05) 25%,',
-            'rgba(0,0,0,0.05) 75%,',
-            'rgba(0,0,0,0.02) 75%,',
-            'rgba(0,0,0,0.02)',
-        ') center center / 10px 10px repeat scroll'
-    ].join('');
     var srcProps = {
         'iframe': 'src',
         'img': 'src'
@@ -205,7 +187,7 @@ var collapser = (function() {
             return;
         }
         var collapse = response.collapse;
-        var bgImg = backgroundImage;
+        var bgImg = response.backgroundImage;
         var i = requests.length;
         var request, entry, target, tagName;
         while ( i-- ) {

src/js/messaging.js

@@ -509,6 +509,9 @@ var onMessage = function(request, sender, callback) {
             collapse: µm.userSettings.collapseBlocked,
             requests: evaluateURLs(tabId, request.requests)
         };
+        if ( !response.collapse ) {
+            response.backgroundImage = vAPI.localStorage.getItem('placeholderBackgroundImage');
+        }
         break;
 
     case 'getUserAgentReplaceStr':

src/js/start.js

@@ -44,6 +44,24 @@ var µm = µMatrix;
 
 /******************************************************************************/
 
+// Browser data jobs
+
+var jobCallback = function() {
+    if ( !µm.userSettings.clearBrowserCache ) {
+        return;
+    }
+    µm.clearBrowserCacheCycle -= 15;
+    if ( µm.clearBrowserCacheCycle > 0 ) {
+        return;
+    }
+    µm.clearBrowserCacheCycle = µm.userSettings.clearBrowserCacheAfter;
+    µm.browserCacheClearedCounter++;
+    vAPI.browserCache.clearByTime(0);
+    // console.debug('clearBrowserCacheCallback()> vAPI.browserCache.clearByTime() called');
+};
+
+/******************************************************************************/
+
 var onAllDone = function() {
     µm.webRequest.start();
 
@@ -54,26 +72,31 @@ var onAllDone = function() {
     µm.assetUpdater.onAssetUpdated.addListener(µm.assetUpdatedHandler.bind(µm));
     µm.assets.onAssetCacheRemoved.addListener(µm.assetCacheRemovedHandler.bind(µm));
 
-    // Browser data jobs
-    var jobCallback = function() {
-        if ( !µm.userSettings.clearBrowserCache ) {
-            return;
-        }
-        µm.clearBrowserCacheCycle -= 15;
-        if ( µm.clearBrowserCacheCycle > 0 ) {
-            return;
-        }
-        µm.clearBrowserCacheCycle = µm.userSettings.clearBrowserCacheAfter;
-        µm.browserCacheClearedCounter++;
-        vAPI.browserCache.clearByTime(0);
-        // console.debug('clearBrowserCacheCallback()> vAPI.browserCache.clearByTime() called');
-    };
-
     µMatrix.asyncJobs.add('clearBrowserCache', null, jobCallback, 15 * 60 * 1000, true);
 
     // Important: remove barrier to remote fetching, this was useful only
     // for launch time.
     µm.assets.remoteFetchBarrier -= 1;
+
+    if ( vAPI.localStorage.getItem('placeholderBackgroundImage') === null ) {
+        vAPI.localStorage.setItem('placeholderBackgroundImage', [
+            'linear-gradient(0deg,',
+                'rgba(0,0,0,0.02) 25%,',
+                'rgba(0,0,0,0.05) 25%,',
+                'rgba(0,0,0,0.05) 75%,',
+                'rgba(0,0,0,0.02) 75%,',
+                'rgba(0,0,0,0.02)',
+            ') center center / 10px 10px repeat scroll,',
+            'linear-gradient(',
+                '90deg,',
+                'rgba(0,0,0,0.02) 25%,',
+                'rgba(0,0,0,0.05) 25%,',
+                'rgba(0,0,0,0.05) 75%,',
+                'rgba(0,0,0,0.02) 75%,',
+                'rgba(0,0,0,0.02)',
+            ') center center / 10px 10px repeat scroll'
+        ].join(''));
+    }
 };
 
 var onTabsReady = function(tabs) {