Fixed drag and drop into and out of Browser Plugin.

content/browser/browser_plugin/browser_plugin_embedder.cc

Index: content/browser/browser_plugin/browser_plugin_embedder.cc
diff --git a/content/browser/browser_plugin/browser_plugin_embedder.cc b/content/browser/browser_plugin/browser_plugin_embedder.cc
index 4ffaa3d7b383bdb45bb84d562e2a17ae8b070f4e..618e61f8d888bb35e497d47ea50b52a4b7da8517 100644
--- a/content/browser/browser_plugin/browser_plugin_embedder.cc
+++ b/content/browser/browser_plugin/browser_plugin_embedder.cc
@@ -11,6 +11,7 @@
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/common/browser_plugin_messages.h"
+#include "content/common/drag_messages.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_service.h"
@@ -195,6 +196,22 @@ BrowserPluginGuest* BrowserPluginEmbedder::GetGuestByInstanceID(
   return NULL;
 }
 
+void BrowserPluginEmbedder::DragEnteredGuest(BrowserPluginGuest* guest) {
+  guest_dragging_over_ = guest->AsWeakPtr();
+}
+
+void BrowserPluginEmbedder::DragLeftGuest(BrowserPluginGuest* guest) {
+  // Avoid race conditions in switching between guests being hovered over by
+  // only un-setting if the caller is marked as the guest being dragged over.
+  if (guest_dragging_over_.get() == guest) {
+    guest_dragging_over_.reset();
+  }
+}
+
+void BrowserPluginEmbedder::StartDrag(BrowserPluginGuest* guest) {
+  guest_started_drag_ = guest->AsWeakPtr();
+}
+
 void BrowserPluginEmbedder::DestroyGuestByInstanceID(int instance_id) {
   BrowserPluginGuest* guest = GetGuestByInstanceID(instance_id);
   if (guest) {
@@ -250,11 +267,25 @@ bool BrowserPluginEmbedder::OnMessageReceived(const IPC::Message& message) {
                         OnPluginDestroyed)
     IPC_MESSAGE_HANDLER(BrowserPluginHostMsg_BuffersSwappedACK,
                         OnSwapBuffersACK)
+    IPC_MESSAGE_HANDLER_GENERIC(DragHostMsg_UpdateDragCursor,
+                                OnUpdateDragCursor(&handled));
+    IPC_MESSAGE_HANDLER_GENERIC(DragHostMsg_DragStopped,
+                                OnDragStopped(message, &handled));
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
+void BrowserPluginEmbedder::OnDragStopped(const IPC::Message& message,
+    bool* handled) {
+  if (guest_started_drag_.get())
+    *handled = guest_started_drag_->OnMessageReceived(message);
+}
+
+void BrowserPluginEmbedder::OnUpdateDragCursor(bool* handled) {
+  *handled = guest_dragging_over_.get();
+}
+
 void BrowserPluginEmbedder::Observe(int type,
                                     const NotificationSource& source,
                                     const NotificationDetails& details) {