Fix UaF of BlinkTestRunner caused by incorrect base::Unretained.

content/shell/renderer/layout_test/blink_test_runner.cc

Index: content/shell/renderer/layout_test/blink_test_runner.cc
diff --git a/content/shell/renderer/layout_test/blink_test_runner.cc b/content/shell/renderer/layout_test/blink_test_runner.cc
index 5d2f98a9482e51b64b047808fb36ffbecdf32655..20d87dd8fb5242e2ea5f0bc8b49d4c5b300b7b3c 100644
--- a/content/shell/renderer/layout_test/blink_test_runner.cc
+++ b/content/shell/renderer/layout_test/blink_test_runner.cc
@@ -903,10 +903,7 @@ void BlinkTestRunner::OnPixelsDumpCompleted(const SkBitmap& snapshot) {
 void BlinkTestRunner::CaptureDumpComplete() {
   render_view()->GetWebView()->mainFrame()->stopLoading();
 
-  base::ThreadTaskRunnerHandle::Get()->PostTask(
-      FROM_HERE, base::Bind(base::IgnoreResult(&BlinkTestRunner::Send),
-                            base::Unretained(this),
-                            new ShellViewHostMsg_TestFinished(routing_id())));
+  Send(new ShellViewHostMsg_TestFinished(routing_id()));

[Łukasz Anforowicz, 2016/04/06 22:45:28]

The asynchronous posting came from
https://chromium.googlesource.com/chromium/src/+/8b68e2bd35dbe83be805a8665a26...

I am not sure I understand why the indirection might be needed here in the past
- sending synchronously should be fine IMO, because:
1. I would expect that the act of sending should have no impact on layers above
IPC
2. Effect of sending an IPC is asynchronous (regardless whether Send is called
synchronously or posted asynchronously)

The new code seems ok to land to me:
1. tests still pass
2. no UaF
3. one less base::Unretained

WDYT?

 }
 
 mojom::LayoutTestBluetoothFakeAdapterSetter&