Bug 1055261 - Reduce new tab performance impact by only attempting to show 5 columns (from 8) [r=adw]

browser/app/profile/firefox.js

@@ -1522,7 +1522,7 @@ pref("browser.newtabpage.enhanced", false);
 pref("browser.newtabpage.rows", 3);
 
 // number of columns of newtab grid
-pref("browser.newtabpage.columns", 8);
+pref("browser.newtabpage.columns", 5);
 
 // directory tiles download URL
 pref("browser.newtabpage.directory.source", "chrome://global/content/directoryLinks.json");

browser/base/content/test/newtab/browser_newtab_bug752841.js

@@ -17,8 +17,8 @@ function runTests() {
   // Expected length of grid
   let expectedValues = [1, 1, 1, 1, 8, 10];
 
-   // Values before setting new pref values (24 is the default value -> 8 x 3)
-  let previousValues = [24, 1, 1, 1, 1, 8];
+   // Values before setting new pref values (15 is the default value -> 5 x 3)
+  let previousValues = [15, 1, 1, 1, 1, 8];
 
   let existingTab, existingTabGridLength, newTab, newTabGridLength;
   yield addNewTabPageTab();