Clang: Add revision and completion management

Reparsing a document is expensive so we should avoid it by all means. In
this patch we prevent that the same document is send again. It isn't send
too in advance of a code completion if there was no changes before the
the completion position.

Change-Id: I0bb786ba1d4e7ce08611a518cb32f8cf8f4d0037
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

src/plugins/cpptools/editordocumenthandle.cpp

@@ -58,4 +58,9 @@ void CppEditorDocumentHandle::setNeedsRefresh(bool needsRefresh)
     m_needsRefresh = needsRefresh;
 }
 
+SendDocumentTracker &CppEditorDocumentHandle::sendTracker(const QString &projectPartId)
+{
+    return m_documentRevisionManagements[projectPartId];
+}
+
 } // namespace CppTools