Implement ui::ClipboardMus.

ui/base/clipboard/clipboard.cc

Index: ui/base/clipboard/clipboard.cc
diff --git a/ui/base/clipboard/clipboard.cc b/ui/base/clipboard/clipboard.cc
index d43954bbc31d39fc7db5bcbc7fe645ae34599f8e..ec6bb321a5fe27499dd1234aa46d544dc6be1133 100644
--- a/ui/base/clipboard/clipboard.cc
+++ b/ui/base/clipboard/clipboard.cc
@@ -32,24 +32,27 @@ void Clipboard::SetAllowedThreads(
 }
 
 // static
-Clipboard* Clipboard::GetForCurrentThread() {
+void Clipboard::SetClipboardForCurrentThread(
+    std::unique_ptr<Clipboard> platform_clipboard) {
   base::AutoLock lock(clipboard_map_lock_.Get());
+  base::PlatformThreadId id = Clipboard::GetAndValidateThreadID();
 
-  base::PlatformThreadId id = base::PlatformThread::CurrentId();
-
-  AllowedThreadsVector* allowed_threads = allowed_threads_.Pointer();
-  if (!allowed_threads->empty()) {
-    bool found = false;
-    for (AllowedThreadsVector::const_iterator it = allowed_threads->begin();
-         it != allowed_threads->end(); ++it) {
-      if (*it == id) {
-        found = true;
-        break;
-      }
-    }
-
-    DCHECK(found);
+  ClipboardMap* clipboard_map = clipboard_map_.Pointer();
+  ClipboardMap::const_iterator it = clipboard_map->find(id);
+  if (it != clipboard_map->end()) {
+    // This is suboptimal, but because the timing of how we create
+    // WindowManagerConnection, we can end up having created a Clipboard object
+    // before we've established our first mojo connection to mus.

[dcheng, 2016/06/04 06:14:00]

I'm a little worried about potential side effects of swapping out the Clipboard
implementation… there's no way to change things so we can order things more
sanely here?

[Elliot Glaysher, 2016/06/06 20:10:12]

This was entirely my fault. Fixed.

+    delete it->second;

[dcheng, 2016/06/04 06:14:00]

We may as well fix the clipboard map to store unique_ptrs.

[Elliot Glaysher, 2016/06/06 20:10:12]

Done.

+    clipboard_map->erase(it);
   }
+  clipboard_map->insert(std::make_pair(id, platform_clipboard.release()));
+}
+
+// static
+Clipboard* Clipboard::GetForCurrentThread() {
+  base::AutoLock lock(clipboard_map_lock_.Get());
+  base::PlatformThreadId id = GetAndValidateThreadID();
 
   ClipboardMap* clipboard_map = clipboard_map_.Pointer();
   ClipboardMap::const_iterator it = clipboard_map->find(id);
@@ -132,4 +135,25 @@ void Clipboard::DispatchObject(ObjectType type, const ObjectMapParams& params) {
   }
 }
 
+base::PlatformThreadId Clipboard::GetAndValidateThreadID() {
+  base::PlatformThreadId id = base::PlatformThread::CurrentId();
+#ifndef NDEBUG
+  AllowedThreadsVector* allowed_threads = allowed_threads_.Pointer();
+  if (!allowed_threads->empty()) {
+    bool found = false;
+    for (AllowedThreadsVector::const_iterator it = allowed_threads->begin();
+         it != allowed_threads->end(); ++it) {
+      if (*it == id) {
+        found = true;
+        break;
+      }
+    }
+
+    DCHECK(found);
+  }
+#endif
+
+  return id;
+}
+
 }  // namespace ui