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/bench/DecodeBench.cpp b/bench/DecodeBench.cpp
index a4717f8..b03f898 100644
--- a/bench/DecodeBench.cpp
+++ b/bench/DecodeBench.cpp
@@ -20,7 +20,7 @@
     SkString          fName;
 public:
     DecodeBench(SkColorType ct) : fPrefColorType(ct) {
-        SkString fname = SkOSPath::SkBasename(FLAGS_decodeBenchFilename[0]);
+        SkString fname = SkOSPath::Basename(FLAGS_decodeBenchFilename[0]);
         fName.printf("decode_%s_%s", sk_tool_utils::colortype_name(ct), fname.c_str());
     }
 
diff --git a/bench/ImageDecodeBench.cpp b/bench/ImageDecodeBench.cpp
index 47993cf..3ce2fb0 100644
--- a/bench/ImageDecodeBench.cpp
+++ b/bench/ImageDecodeBench.cpp
@@ -25,7 +25,7 @@
     , fFilename(filename)
     , fStream()
     , fValid(false) {
-        fName.append(SkOSPath::SkBasename(filename));
+        fName.append(SkOSPath::Basename(filename));
     }
 
     virtual bool isSuitableFor(Backend backend) SK_OVERRIDE {
diff --git a/bench/SkipZeroesBench.cpp b/bench/SkipZeroesBench.cpp
index 30d9377..fc25f8b 100644
--- a/bench/SkipZeroesBench.cpp
+++ b/bench/SkipZeroesBench.cpp
@@ -52,8 +52,7 @@
             return;
         }
 
-        SkString fullPath = SkOSPath::SkPathJoin(resourcePath.c_str(),
-                                                 fFilename.c_str());
+        SkString fullPath = SkOSPath::Join(resourcePath.c_str(), fFilename.c_str());
         SkFILEStream fileStream(fullPath.c_str());
         fValid = fileStream.isValid() && fileStream.getLength() > 0;
         if (fValid) {
diff --git a/bench/benchmain.cpp b/bench/benchmain.cpp
index f3fdb9f..9c5f0e9 100644
--- a/bench/benchmain.cpp
+++ b/bench/benchmain.cpp
@@ -108,7 +108,7 @@
     SkString filename;
     make_filename(name, &filename);
     filename.appendf("_%s.png", config);
-    SkString path = SkOSPath::SkPathJoin(dir, filename.c_str());
+    SkString path = SkOSPath::Join(dir, filename.c_str());
     ::remove(path.c_str());
 
     SkFILEWStream   stream(path.c_str());