Solidify Model/View split

Change-Id: Iecf034feaa009002b5f09c47052c915d22aec0e4
Reviewed-on: https://skia-review.googlesource.com/43040
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index 8d9d056..7837aa6 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1710,6 +1710,7 @@
         "tools/debugger/SkJsonWriteBuffer.cpp",
         "tools/debugger/SkObjectParser.cpp",
         "tools/mdbviz/MainWindow.cpp",
+        "tools/mdbviz/Model.cpp",
         "tools/mdbviz/main.cpp",
         "tools/picture_utils.cpp",