Allow chrome.debugger API to attach to extension background pages.

chrome/test/data/extensions/api_test/debugger/background.js

Index: chrome/test/data/extensions/api_test/debugger/background.js
diff --git a/chrome/test/data/extensions/api_test/debugger/background.js b/chrome/test/data/extensions/api_test/debugger/background.js
index 0ca46c96a3bb130dba39384b31f4233213b97be4..35a02514bb8ea03fde52a0ab38fbfe6de9e4320a 100644
--- a/chrome/test/data/extensions/api_test/debugger/background.js
+++ b/chrome/test/data/extensions/api_test/debugger/background.js
@@ -7,6 +7,7 @@ var fail = chrome.test.callbackFail;
 
 var tabId;
 var debuggee;
+var debuggeeExtension;
 var protocolVersion = "1.0";
 
 chrome.test.runTests([
@@ -40,6 +41,12 @@ chrome.test.runTests([
     });
   },
 
+  function attachToMissingTab() {
+     var missingDebuggee = {tabId: -1};
+     chrome.debugger.attach(missingDebuggee, protocolVersion,
+        fail("No tab with given id " + missingDebuggee.tabId + "."));
+  },
+
   function attachAgain() {
     chrome.debugger.attach(debuggee, protocolVersion,
         fail("Another debugger is already attached to the tab with id: " +
@@ -98,6 +105,40 @@ chrome.test.runTests([
           fail("Can not attach to the page with the \"chrome://\" scheme."));
       chrome.tabs.remove(tab.id);
     });
-  }
+  },
+
+  function attachToExtension() {
+    var extensionId = chrome.extension.getURL('').split('/')[2];
+    debuggeeExtension = {extensionId: extensionId};
+    chrome.debugger.attach(debuggeeExtension, protocolVersion, pass());
+  },
+
+  function attachToMissingExtension() {
+    var missingDebuggee = {extensionId: "foo"};
+    chrome.debugger.attach(missingDebuggee, protocolVersion,
+        fail("No extension with given id " +
+            missingDebuggee.extensionId + "."));
+  },
 
+  function attachToInvalidTarget() {
+    var emptyDebuggee = {};
+    chrome.debugger.attach(emptyDebuggee, protocolVersion,
+        fail("Either tab id or extension id must be specified."));
+  },
+
+  function attachAgainToExtension() {
+    chrome.debugger.attach(debuggeeExtension, protocolVersion,
+        fail("Another debugger is already attached to the extension with id: " +
+            debuggeeExtension.extensionId + "."));
+  },
+
+  function detachFromExtension() {
+    chrome.debugger.detach(debuggeeExtension, pass());
+  },
+
+  function detachAgainFromExtension() {
+    chrome.debugger.detach(debuggeeExtension,
+        fail("Debugger is not attached to the extension with id: " +
+            debuggeeExtension.extensionId + "."));
+  },
 ]);