Fix base::CopyDirectory() and JumpListIcons(Old) folders' operation logic

base/files/file_util_win.cc

Index: base/files/file_util_win.cc
diff --git a/base/files/file_util_win.cc b/base/files/file_util_win.cc
index d70454df3836a7067f71eecf5a0ae8673376f474..d1fc25f43cc0a86c8253731d387c7b2c5c6bf854 100644
--- a/base/files/file_util_win.cc
+++ b/base/files/file_util_win.cc
@@ -177,9 +177,16 @@ bool CopyDirectory(const FilePath& from_path, const FilePath& to_path,
   FilePath real_from_path = MakeAbsoluteFilePath(from_path);
   if (real_from_path.empty())
     return false;
+  // Originally this CopyDirectory() returns false when |to_path| string
+  // contains |from_path| string. While this can be that the to_path is within
+  // the from_path, e.g., parent-child relationship if they are both folders, it
+  // also can be that the two paths are in the same folder, just that one name
+  // contains the other, e.g. C:\\JumpListIcon and C:\\JumpListIconOld.

[gab, 2016/12/13 21:31:21]

s/JumpListIcon/Foo/ in example (since this is in //base)

also no need to escape the \ in a comment :)

[chengx, 2016/12/13 23:00:39]

Done.

+  // We make this function not return false in the latter situation by calling
+  // IsParent() function as below. This allows the copy-n-delete code after the
+  // "return false" below to execute.

[gab, 2016/12/13 21:31:21]

No need to describe history here IMO, just say:

// Note: it's important to use IsParent() here as string comparison would result
in a false positive on, e.g. C:\Foo versus C:\FooOld.

[chengx, 2016/12/13 23:00:39]

Done.

   if (real_to_path.value().size() >= real_from_path.value().size() &&
-      real_to_path.value().compare(0, real_from_path.value().size(),
-                                   real_from_path.value()) == 0) {
+      real_from_path.IsParent(real_to_path)) {
     return false;
   }