signin: force web signin flow initiated visits to accounts.google.com to their own process.

chrome/renderer/chrome_content_renderer_client.cc

Index: chrome/renderer/chrome_content_renderer_client.cc
diff --git a/chrome/renderer/chrome_content_renderer_client.cc b/chrome/renderer/chrome_content_renderer_client.cc
index 0a28d0f0c00f5433041fbf7d1d05e903ae5ff555..d4a65fdcc46ea27b0ca7ad04e5ee53bbf6be4f05 100644
--- a/chrome/renderer/chrome_content_renderer_client.cc
+++ b/chrome/renderer/chrome_content_renderer_client.cc
@@ -844,6 +844,17 @@ bool ChromeContentRendererClient::ShouldFork(WebFrame* frame,
   if (http_method != "GET")
     return false;
 
+  // If this is the Signin process, fork all navigations originating from the
+  // renderer.  The destination page will then be bucketed back to this Signin
+  // process if it is a Signin url, or to another process if not.
+  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kSigninProcess)) {
+    // We explicitly do this *after* checking that http_method is not POST,

[darin (slow to review), 2013/03/05 07:29:56]

nit: I'm confused by this comment.  It seems like this code will only matter
once we fix http://crbug.com/101395.

[tim (not reviewing), 2013/03/05 09:45:25]

You're right, because the if-statement on line 844 above will prevent us from
ever getting here with http_method == POST.  However, it seemed prudent to add
an extra check in the event that bug 101395 is fixed, so that we're forced to
think of this case before opening the floodgates and have to add the ability to
check whether we're posting to a valid signin URL.  

Does that sound right to you?

+    // because we don't want to allow non-signin pages to fork-on-POST to a
+    // signin-related action URL.
+    CHECK_NE(http_method, "POST");
+    return true;
+  }
+
   // If |url| matches one of the prerendered URLs, stop this navigation and try
   // to swap in the prerendered page on the browser process. If the prerendered
   // page no longer exists by the time the OpenURL IPC is handled, a normal