background.js

var BLOGGER_NEW_UI_EDITOR_URL = /^https?:\/\/(?:www|draft)\.blogger\.com\/blogger\.g\?.*#editor\b/;
var BLOGGER_OLD_UI_EDITOR_URL = /^https?:\/\/(?:www|draft)\.blogger\.com\/post-(?:create|edit)\.g\?/;
var GMAIL_URL = /^https:\/\/mail\.google\.com\//;
var FACEBOOK_URL = /^https:\/\/www\.facebook\.com\//;
var arr = [];

function onTabEvent(tabId) {
  chrome.tabs.get(tabId, function(tab) {
    if (BLOGGER_NEW_UI_EDITOR_URL.test(tab.url) ||
        BLOGGER_OLD_UI_EDITOR_URL.test(tab.url) ||
        FACEBOOK_URL.test(tab.url) ||
        GMAIL_URL.test(tab.url)) {
      chrome.pageAction.show(tab.id);
      arr.push(tab.id);
    } else {
      chrome.pageAction.hide(tab.id);
    }
  });
}

function onPageActionClick(tab) {
  chrome.tabs.executeScript(tab.id, {'file': 'changequotes.js'});
}

chrome.tabs.onUpdated.addListener(onTabEvent);
chrome.tabs.onActiveChanged.addListener(onTabEvent);
chrome.pageAction.onClicked.addListener(onPageActionClick);
chrome.commands.onCommand.addListener(function(command) {
    if (command == "punctuate") {
        chrome.tabs.getSelected(null, function(tab){
            onPageActionClick(tab);
            //chrome.tabs.executeScript(tab.id, {'file': 'changequotes.js'});
        });
    }
});