mus: Remove window server access to clipboard and the drag clipboard.

This reverts 7d6c8b29, which made window server have access to the
clipboard, as at the time, I thought that drag and drop would read/write
to/from a dedicated drag clipboard and that the window server would have
to manipulate it. Due to timing issues, this didn't work out.

Now that we aren't using a drag clipboard as the backing for mus drag
and drop, also remove the drag clipboard from our mus clipboard
implementation.

BUG=614037

Review-Url: https://codereview.chromium.org/2339353003
Cr-Commit-Position: refs/heads/master@{#419260}

services/ui/clipboard/clipboard_impl.h

@@ -26,7 +26,7 @@ namespace clipboard {
 class ClipboardImpl : public mojom::Clipboard {
  public:
   // mojom::Clipboard exposes three possible clipboards.
-  static const int kNumClipboards = 3;
+  static const int kNumClipboards = 2;
 
   ClipboardImpl();
   ~ClipboardImpl() override;

services/ui/public/interfaces/clipboard.mojom

@@ -15,8 +15,7 @@ const string kMimeTypeURL = "text/url";
 interface Clipboard {
   enum Type {
     COPY_PASTE = 0,
-    SELECTION = 1,
-    DRAG = 2
+    SELECTION = 1
   };
 
   // Returns a sequence number which uniquely identifies clipboard state.

services/ui/service.cc

@@ -76,6 +76,7 @@ struct Service::PendingRequest {
 };
 
 struct Service::UserState {
+  std::unique_ptr<clipboard::ClipboardImpl> clipboard;
   std::unique_ptr<ws::AccessibilityManager> accessibility;
   std::unique_ptr<ws::WindowTreeHostFactory> window_tree_host_factory;
 };
@@ -269,8 +270,10 @@ void Service::Create(const shell::Identity& remote_identity,
 
 void Service::Create(const shell::Identity& remote_identity,
                      mojom::ClipboardRequest request) {
-  const ws::UserId& user_id = remote_identity.user_id();
-  window_server_->GetClipboardForUser(user_id)->AddBinding(std::move(request));
+  UserState* user_state = GetUserState(remote_identity);
+  if (!user_state->clipboard)
+    user_state->clipboard.reset(new clipboard::ClipboardImpl);
+  user_state->clipboard->AddBinding(std::move(request));
 }
 
 void Service::Create(const shell::Identity& remote_identity,

services/ui/ws/BUILD.gn

@@ -129,7 +129,6 @@ static_library("lib") {
     "//services/shell/public/cpp",
     "//services/shell/public/interfaces",
     "//services/tracing/public/cpp",
-    "//services/ui/clipboard:lib",
     "//services/ui/common:mus_common",
     "//services/ui/display",
     "//services/ui/public/interfaces",

services/ui/ws/window_server.cc

@@ -248,12 +248,6 @@ void WindowServer::OnFirstWindowManagerWindowTreeFactoryReady() {
   delegate_->CreateDefaultDisplays();
 }
 
-ui::clipboard::ClipboardImpl* WindowServer::GetClipboardForUser(
-    const UserId& user_id) {
-  DCHECK_GT(clipboard_map_.count(user_id), 0u);
-  return clipboard_map_[user_id].get();
-}
-
 UserActivityMonitor* WindowServer::GetUserActivityMonitorForUser(
     const UserId& user_id) {
   DCHECK_GT(activity_monitor_map_.count(user_id), 0u);
@@ -825,12 +819,10 @@ void WindowServer::OnActiveUserIdChanged(const UserId& previously_active_id,
 
 void WindowServer::OnUserIdAdded(const UserId& id) {
   activity_monitor_map_[id] = base::MakeUnique<UserActivityMonitor>(nullptr);
-  clipboard_map_[id] = base::MakeUnique<clipboard::ClipboardImpl>();
 }
 
 void WindowServer::OnUserIdRemoved(const UserId& id) {
   activity_monitor_map_.erase(id);
-  clipboard_map_.erase(id);
 }
 
 }  // namespace ws

services/ui/ws/window_server.h

@@ -16,7 +16,6 @@
 #include "base/optional.h"
 #include "mojo/public/cpp/bindings/array.h"
 #include "mojo/public/cpp/bindings/binding.h"
-#include "services/ui/clipboard/clipboard_impl.h"
 #include "services/ui/public/interfaces/window_manager_window_tree_factory.mojom.h"
 #include "services/ui/public/interfaces/window_tree.mojom.h"
 #include "services/ui/public/interfaces/window_tree_host.mojom.h"
@@ -137,8 +136,6 @@ class WindowServer : public ServerWindowDelegate,
 
   void OnFirstWindowManagerWindowTreeFactoryReady();
 
-  clipboard::ClipboardImpl* GetClipboardForUser(const UserId& user_id);
-
   UserActivityMonitor* GetUserActivityMonitorForUser(const UserId& user_id);
 
   WindowManagerWindowTreeFactorySet* window_manager_window_tree_factory_set() {
@@ -251,8 +248,6 @@ class WindowServer : public ServerWindowDelegate,
       std::map<ClientSpecificId, std::unique_ptr<WindowTree>>;
   using UserActivityMonitorMap =
       std::map<UserId, std::unique_ptr<UserActivityMonitor>>;
-  using UserClipboardMap =
-      std::map<UserId, std::unique_ptr<ui::clipboard::ClipboardImpl>>;
 
   struct InFlightWindowManagerChange {
     // Identifies the client that initiated the change.
@@ -382,7 +377,6 @@ class WindowServer : public ServerWindowDelegate,
   base::Callback<void(ServerWindow*)> window_paint_callback_;
 
   UserActivityMonitorMap activity_monitor_map_;
-  UserClipboardMap clipboard_map_;
 
   WindowManagerWindowTreeFactorySet window_manager_window_tree_factory_set_;
 

ui/views/mus/clipboard_mus.cc

@@ -24,7 +24,8 @@ ui::mojom::Clipboard::Type GetType(ui::ClipboardType type) {
     case ui::CLIPBOARD_TYPE_SELECTION:
       return ui::mojom::Clipboard::Type::SELECTION;
     case ui::CLIPBOARD_TYPE_DRAG:
-      return ui::mojom::Clipboard::Type::DRAG;
+      // Only OSX uses a drag clipboard.
+      break;
   }
 
   NOTREACHED();