Introduce background.scripts feature for extension manifests.

chrome/common/extensions/extension.h

Index: chrome/common/extensions/extension.h
diff --git a/chrome/common/extensions/extension.h b/chrome/common/extensions/extension.h
index 8955544b0fdfe289665dfa17a560f70de3cb51d3..46717b16250faedea802100a9f89ec2524392ae5 100644
--- a/chrome/common/extensions/extension.h
+++ b/chrome/common/extensions/extension.h
@@ -531,7 +531,12 @@ class Extension : public base::RefCountedThreadSafe<Extension> {
   const std::vector<InputComponentInfo>& input_components() const {
     return input_components_;
   }
-  const GURL& background_url() const { return background_url_; }
+  bool has_background_page() const {
+    return background_url_.is_valid() || !background_scripts_.empty();
+  }
+  const std::vector<std::string>& background_scripts() const {
+    return background_scripts_;
+  }
   const GURL& options_url() const { return options_url_; }
   const GURL& devtools_url() const { return devtools_url_; }
   const ExtensionPermissionSet* optional_permission_set() const {
@@ -593,6 +598,8 @@ class Extension : public base::RefCountedThreadSafe<Extension> {
     return theme_display_properties_.get();
   }
 
+  GURL GetBackgroundURL() const;
+
  private:
   friend class base::RefCountedThreadSafe<Extension>;
 
@@ -669,6 +676,8 @@ class Extension : public base::RefCountedThreadSafe<Extension> {
                         string16* error);
   bool LoadWebIntentServices(const extensions::Manifest* manifest,
                              string16* error);
+  bool LoadBackgroundScripts(const extensions::Manifest* manifest,
+                             string16* error);
   bool LoadBackgroundPage(const extensions::Manifest* manifest,
                           const ExtensionAPIPermissionSet& api_permissions,
                           string16* error);
@@ -809,6 +818,10 @@ class Extension : public base::RefCountedThreadSafe<Extension> {
   // loaded in the background.
   GURL background_url_;
 
+  // Optional list of scripts to use to generate a background page. If this is
+  // present, background_url_ will be empty and generated by GetBackgroundURL().
+  std::vector<std::string> background_scripts_;
+
   // Optional URL to a page for setting options/preferences.
   GURL options_url_;