[Extensions] Quick semantic change to matching extension files.

Bug: None
Change-Id: Id27c9db1a9803149229ebf138ba6a8e729da2833
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2450727
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Commit-Queue: Solomon Kinard <solomonkinard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#817146}

chrome/browser/extensions/tab_helper.h

@@ -55,7 +55,7 @@ class TabHelper : public content::WebContentsObserver,
   //
   // NOTE: this should only be manipulated before the tab is added to a browser.
   // TODO(sky): resolve if this is the right way to identify an app tab. If it
-  // is, than this should be passed in the constructor.
+  // is, then this should be passed in the constructor.
   void SetExtensionApp(const Extension* extension);
 
   // Convenience for setting the app extension by id. This does nothing if

chrome/common/extensions/docs/templates/intros/declarativeWebRequest.html

@@ -37,7 +37,7 @@ All other actions require host permissions to all URLs.
 </p>
 <p>
 As an example, if <code>"*://*.google.com/*"</code> is the only host permission
-an extension has, than such an extension may set up a rule to
+an extension has, then such an extension may set up a rule to
 <ul>
   <li> cancel a request to "http://www.google.com" or "http://anything.else.com"
   <li> send a message when navigating to "http://www.google.com" but not to

chrome/test/data/extensions/api_test/tabs/basics/events.js

@@ -48,7 +48,7 @@ chrome.test.runTests([
         // Test that |tabid| matches this id.
         assertEq(tabid, tab.id);
 
-        // If |changeInfo| has a status property, than
+        // If |changeInfo| has a status property, then
         // it should match the status of the tab in |tab|.
         if (changeInfo.status) {
           assertEq(changeInfo.status, tab.status);

chromecast/browser/extensions/cast_extension_system.cc

@@ -45,7 +45,7 @@ std::unique_ptr<base::DictionaryValue> LoadManifestFromString(
   std::unique_ptr<base::Value> root(deserializer.Deserialize(nullptr, error));
   if (!root.get()) {
     if (error->empty()) {
-      // If |error| is empty, than the file could not be read.
+      // If |error| is empty, then the file could not be read.
       // It would be cleaner to have the JSON reader give a specific error
       // in this case, but other code tests for a file error with
       // error->empty().  For now, be consistent.