Stick windows to sides of workspaces

ash/wm/workspace/workspace_window_resizer.h

Index: ash/wm/workspace/workspace_window_resizer.h
diff --git a/ash/wm/workspace/workspace_window_resizer.h b/ash/wm/workspace/workspace_window_resizer.h
index 424e47d29f4890086fa5d3e49d694360e1a3eb2b..54d7d2f226f9c2387eaa0b9deb7a46133b45ec99 100644
--- a/ash/wm/workspace/workspace_window_resizer.h
+++ b/ash/wm/workspace/workspace_window_resizer.h
@@ -101,6 +101,10 @@ class ASH_EXPORT WorkspaceWindowResizer : public WindowResizer {
       int available_size,
       std::vector<int>* sizes) const;
 
+  // Returns a bitmask of all edges touching the dock bounds when dock is not
+  // opened yet or the edge representing the side that the dock is opened on.
+  int CalculateDockEdges(const gfx::Rect& bounds) const;
+
   // Divides |amount| evenly between |sizes|. If |amount| is negative it
   // indicates how many pixels |sizes| should be shrunk by.
   // Returns how many pixels failed to be allocated/removed from |sizes|.
@@ -190,6 +194,9 @@ class ASH_EXPORT WorkspaceWindowResizer : public WindowResizer {
   // Last SnapType.
   SnapType snap_type_;
 
+  // Last updated bitmask of all touched edges.
+  mutable int dock_edges_mask_;
+
   // Number of mouse moves since the last bounds change. Only used for phantom
   // placement to track when the mouse is moved while pushed against the edge of
   // the screen.