Validate debuggee.targetId before use in chrome.debugger

chrome/browser/extensions/api/debugger/debugger_api.cc

Index: chrome/browser/extensions/api/debugger/debugger_api.cc
diff --git a/chrome/browser/extensions/api/debugger/debugger_api.cc b/chrome/browser/extensions/api/debugger/debugger_api.cc
index f927fcb3545f25721ea8c71a591f9a133f7161e7..4dc711f3b8d53ebcfaad7c1e536db4fd2e1c273f 100644
--- a/chrome/browser/extensions/api/debugger/debugger_api.cc
+++ b/chrome/browser/extensions/api/debugger/debugger_api.cc
@@ -529,6 +529,15 @@ bool DebuggerFunction::InitAgentHost() {
     }
   } else if (debuggee_.target_id) {
     agent_host_ = DevToolsAgentHost::GetForId(*debuggee_.target_id);
+    if (agent_host_.get()) {
+      if (PermissionsData::IsRestrictedUrl(agent_host_->GetURL(),

[Devlin, 2015/02/09 23:11:22]

I'm a little worried about race conditions here, if, for instance, the debugger
is attached before the url is fully resolved. Not sure how much we can do about
it, but a sanity check that url is_valid() would probably be better than
nothing.

[robwu, 2015/02/10 12:56:31]

Isn't the IsValidSchemeForExtensions check in PermissionsData::IsRestrictedUrl
sufficient?

[Devlin, 2015/02/10 17:14:42]

Yeah, that'd probably work.  Nevermind.

+                                           agent_host_->GetURL(),
+                                           extension(),
+                                           &error_)) {
+        agent_host_ = NULL;

[Devlin, 2015/02/09 23:11:22]

nit: prefer nullptr now.

[robwu, 2015/02/10 12:56:31]

Done, but the rest of the file still uses NULL (should I change back to NULL,
replace the rest with nullptr, or leave it as-is?).

[Devlin, 2015/02/10 17:14:42]

The rule for nullptr is pretty much just "prefer nullptr".  So it's worth using
in new code, or when refactoring old code, but probably not worth contaminating
the git blame history for the whole file (which is why we haven't just done a
repo-wide find-and-replace).

+        return false;
+      }
+    }
   } else {
     error_ = keys::kInvalidTargetError;
     return false;