Move SkOSPath out of include/core.

It is moved to src/utils. It is almost a tool, but has two uses in
src/ports.

The existing SkOSFile.cpp is left empty for the time being since it is
mentioned in Chromium's BUILD.gn for Skia.

Change-Id: I3bb7f7c4214359eb6ab906bfe76737d20bf1d6c7
Reviewed-on: https://skia-review.googlesource.com/4536
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
diff --git a/src/utils/SkOSFile.cpp b/src/utils/SkOSFile.cpp
index a0c003b..e10e674 100644
--- a/src/utils/SkOSFile.cpp
+++ b/src/utils/SkOSFile.cpp
@@ -1,44 +1,6 @@
 /*
- * Copyright 2011 Google Inc.
+ * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
-#include "SkOSFile.h"
-
-SkString SkOSPath::Join(const char *rootPath, const char *relativePath) {
-    SkString result(rootPath);
-    if (!result.endsWith(SkPATH_SEPARATOR) && !result.isEmpty()) {
-        result.appendUnichar(SkPATH_SEPARATOR);
-    }
-    result.append(relativePath);
-    return result;
-}
-
-SkString SkOSPath::Basename(const char* fullPath) {
-    if (!fullPath) {
-        return SkString();
-    }
-    const char* filename = strrchr(fullPath, SkPATH_SEPARATOR);
-    if (nullptr == filename) {
-        filename = fullPath;
-    } else {
-        ++filename;
-    }
-    return SkString(filename);
-}
-
-SkString SkOSPath::Dirname(const char* fullPath) {
-    if (!fullPath) {
-        return SkString();
-    }
-    const char* end = strrchr(fullPath, SkPATH_SEPARATOR);
-    if (nullptr == end) {
-        return SkString();
-    }
-    if (end == fullPath) {
-        SkASSERT(fullPath[0] == SkPATH_SEPARATOR);
-        ++end;
-    }
-    return SkString(fullPath, end - fullPath);
-}