Attempt 2: Allows tab dragging when maximized on aura. To fix it I made it so

ash/wm/workspace/workspace_event_filter.cc

Index: ash/wm/workspace/workspace_event_filter.cc
diff --git a/ash/wm/workspace/workspace_event_filter.cc b/ash/wm/workspace/workspace_event_filter.cc
index 456691183b4bc672fd599a900e4fa2396d5a28d3..effdc2fffa9b334cbb5d02b918cb7477693b4d38 100644
--- a/ash/wm/workspace/workspace_event_filter.cc
+++ b/ash/wm/workspace/workspace_event_filter.cc
@@ -4,6 +4,7 @@
 
 #include "ash/wm/workspace/workspace_event_filter.h"
 
+#include "ash/wm/property_util.h"
 #include "ash/wm/window_frame.h"
 #include "ash/wm/window_util.h"
 #include "ash/wm/workspace/workspace_layout_manager.h"
@@ -66,6 +67,12 @@ WindowResizer* WorkspaceEventFilter::CreateWindowResizer(
     aura::Window* window,
     const gfx::Point& point,
     int window_component) {
+  // Allow dragging maximized windows if it's not tracked by workspace. This is
+  // set by tab dragging code.
+  if (!wm::IsWindowNormal(window) &&
+      (window_component != HTCAPTION || GetTrackedByWorkspace(window))) {
+    return NULL;
+  }
   return
       new WorkspaceWindowResizer(window, point, window_component, grid_size());
 }