Cleanup: Rename SkOSPath functions.

Mostly for brevity and matches better with Python:

Python           | Old C++                 | New C++
os.path.join     | SkOSPath::SkPathJoin    | SkOSPath::Join
os.path.basename | SkOSPath::SkBasename    | SkOSPath::Basename

BUG=None
TEST=make all
R=mtklein@google.com, bsalomon@google.com

Author: tfarina@chromium.org

Review URL: https://codereview.chromium.org/428443002
diff --git a/src/ports/SkFontHost_linux.cpp b/src/ports/SkFontHost_linux.cpp
index 498d69f..891e461 100644
--- a/src/ports/SkFontHost_linux.cpp
+++ b/src/ports/SkFontHost_linux.cpp
@@ -323,7 +323,7 @@
 
         while (iter.next(&name, false)) {
             SkString filename(
-                SkOSPath::SkPathJoin(directory.c_str(), name.c_str()));
+                SkOSPath::Join(directory.c_str(), name.c_str()));
 
             bool isFixedPitch;
             SkString realname;
@@ -354,8 +354,7 @@
             if (name.startsWith(".")) {
                 continue;
             }
-            SkString dirname(
-                SkOSPath::SkPathJoin(directory.c_str(), name.c_str()));
+            SkString dirname(SkOSPath::Join(directory.c_str(), name.c_str()));
             load_directory_fonts(dirname);
         }
     }