Bug 623739 - CPU usage spikes because of animated hidden images. r=dtownsend, a=blocking-final

toolkit/mozapps/extensions/content/extensions.css

@@ -127,6 +127,7 @@ xhtml|link {
 #detail-view:not([upgrade="true"]) .update-postfix,
 #detail-view[active="true"] .disabled-postfix,
 #detail-view[loading] .detail-view-container,
+#detail-view:not([loading]) .alert-container,
 .detail-row:not([value]),
 #search-list[remote="false"] #search-allresults-link {
   display: none;
@@ -156,3 +157,9 @@ xhtml|link {
 .addon .relnotes {
   -moz-user-select: text;
 }
+
+/* Make sure we're not animating hidden images. See bug 623739. */
+#view-port:not([selectedIndex="0"]) #discover-view .loading,
+#discover-view:not([selectedIndex="0"]) .loading {
+  display: none;
+}

toolkit/themes/gnomestripe/mozapps/extensions/extensions.css

@@ -588,10 +588,6 @@
   opacity: 0;
 }
 
-#detail-view:not([loading]) .loading {
-  visibility: collapse;
-}
-
 #detail-view[loading-extended] .loading {
   -moz-box-align: center;
   -moz-box-pack: center;

toolkit/themes/pinstripe/mozapps/extensions/extensions.css

@@ -689,10 +689,6 @@
   opacity: 0;
 }
 
-#detail-view:not([loading]) .loading {
-  visibility: collapse;
-}
-
 #detail-view[loading-extended] .loading {
   opacity: 1;
   -moz-transition-property: opacity;

toolkit/themes/winstripe/mozapps/extensions/extensions.css

@@ -755,10 +755,6 @@
   opacity: 0;
 }
 
-#detail-view:not([loading]) .alert-container {
-  visibility: collapse;
-}
-
 #detail-view[loading-extended] .loading {
   opacity: 1;
   -moz-transition-property: opacity;