TextEditor: get CompletionAssistProvider from editor.

And not from the global object pool. This way, the editors that have
different highlighters for various language dialects, or editors that
support multiple languages in a single editor, can decide themselves on
what CompletionAssistProvider to provide.

Change-Id: Ieebc4a8e7b3de6470fdb8103035aa3b8b2ba6598
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>

src/plugins/cmakeprojectmanager/cmakeeditor.cpp

@@ -29,6 +29,7 @@
 
 #include "cmakeeditor.h"
 
+#include "cmakefilecompletionassist.h"
 #include "cmakehighlighter.h"
 #include "cmakeeditorfactory.h"
 #include "cmakeprojectconstants.h"
@@ -38,6 +39,7 @@
 #include <coreplugin/infobar.h>
 #include <coreplugin/actionmanager/actioncontainer.h>
 #include <coreplugin/actionmanager/actionmanager.h>
+#include <extensionsystem/pluginmanager.h>
 #include <projectexplorer/projectexplorer.h>
 #include <projectexplorer/session.h>
 #include <texteditor/texteditoractionhandler.h>
@@ -77,6 +79,11 @@ Core::Id CMakeEditor::id() const
     return Core::Id(CMakeProjectManager::Constants::CMAKE_EDITOR_ID);
 }
 
+TextEditor::CompletionAssistProvider *CMakeEditor::completionAssistProvider()
+{
+    return ExtensionSystem::PluginManager::getObject<CMakeFileCompletionAssistProvider>();
+}
+
 void CMakeEditor::markAsChanged()
 {
     if (!document()->isModified())