Rewrite clipboard write IPC handling to be easier to understand.

ui/base/test/test_clipboard.cc

Index: ui/base/test/test_clipboard.cc
diff --git a/ui/base/test/test_clipboard.cc b/ui/base/test/test_clipboard.cc
index df51c99ffb0e086c6f4e06cf15bed9b4e289ff5a..cbea7e850c2869087f94c02726f2f190e8d71a47 100644
--- a/ui/base/test/test_clipboard.cc
+++ b/ui/base/test/test_clipboard.cc
@@ -17,10 +17,12 @@ TestClipboard::TestClipboard()
 TestClipboard::~TestClipboard() {
 }
 
-void TestClipboard::UseForCurrentThread() {
+Clipboard* TestClipboard::CreateForCurrentThread() {
   base::AutoLock lock(Clipboard::clipboard_map_lock_.Get());
+  Clipboard* clipboard = new TestClipboard;
   Clipboard::clipboard_map_.Get()[base::PlatformThread::CurrentId()] =
-      new TestClipboard;
+      clipboard;
+  return clipboard;
 }
 
 uint64 TestClipboard::GetSequenceNumber(ClipboardType type) const {