Fix a bug where redirect chain gets lost on process swap.

chrome/test/data/extensions/api_test/webrequest/test_blocking.js

Index: chrome/test/data/extensions/api_test/webrequest/test_blocking.js
diff --git a/chrome/test/data/extensions/api_test/webrequest/test_blocking.js b/chrome/test/data/extensions/api_test/webrequest/test_blocking.js
index a0e6d6f8d36222de5b471948d618f50a31982850..6829044cf885a487c32c5f07834899070f8223e5 100644
--- a/chrome/test/data/extensions/api_test/webrequest/test_blocking.js
+++ b/chrome/test/data/extensions/api_test/webrequest/test_blocking.js
@@ -126,9 +126,6 @@ runTests([
 
   // Navigates to a page with a blocking handler that redirects to a different
   // page.
-  // TODO(mpcomplete): We should see an onBeforeRedirect as well, but our
-  // process switching logic cancels the original redirect request and
-  // starts a new one instead. See http://crbug.com/79520.

[Matt Perry, 2011/12/03 00:30:22]

Regarding new tests, come to think of it, this is exactly the sort of test I
would write for this change. Maybe it's enough?

[Charlie Reis, 2011/12/03 01:39:56]

This does help as a high-level regression test.  I was thinking something like
the tests in resource_dispatcher_host_unittest.cc to help document how a
cross-process redirect is supposed to look.  If you want to wait to add that
until we turn on the feature, I suppose that's ok.

   function complexLoadRedirected() {
     expect(
       [  // events
@@ -140,14 +137,15 @@ runTests([
           },
           retval: {redirectUrl: getURL("simpleLoad/a.html")}
         },
-        { label: "onErrorOccurred-1",
-          event: "onErrorOccurred",
+        { label: "onBeforeRedirect",
+          event: "onBeforeRedirect",
           details: {
             url: getURL("complexLoad/a.html"),
+            redirectUrl: getURL("simpleLoad/a.html"),
+            statusLine: "",
+            statusCode: -1,
             fromCache: false,
-            error: "net::ERR_ABORTED"
-            // Request to chrome-extension:// url has no IP.
-          }
+          },
         },
         { label: "onBeforeRequest-2",
           event: "onBeforeRequest",
@@ -178,7 +176,7 @@ runTests([
         },
       ],
       [  // event order
-        ["onBeforeRequest-1", "onErrorOccurred-1", "onBeforeRequest-2",
+        ["onBeforeRequest-1", "onBeforeRedirect", "onBeforeRequest-2",
          "onResponseStarted", "onCompleted"],
       ],
       {}, // filter