Cleanup usage of GetResourcePath() after commit bcbc1788b478b1e54079318ad073e8490aa66fae.

There was a clean up opportunity left over after
https://skia.googlesource.com/skia/+/bcbc1788b478b1e54079318ad073e8490aa66fae, that could make use of the default parameter of GetResourcePath() function to make some call sites cleaner.

We decided to make it in a separate CL to make reviewer's and author's life easier, so we could catch errors and/or mistakes easily.

BUG=None
TEST=make all && out/Debug/dm && out/Debug/SampleApp
R=mtklein@google.com

Author: tfarina@chromium.org

Review URL: https://codereview.chromium.org/351133003
diff --git a/tests/KtxTest.cpp b/tests/KtxTest.cpp
index e9c4217..83a3546 100644
--- a/tests/KtxTest.cpp
+++ b/tests/KtxTest.cpp
@@ -141,12 +141,11 @@
  * the PKM to the KTX should produce an identical KTX to the one we have on file)
  */
 DEF_TEST(KtxReexportPKM, reporter) {
-    SkString resourcePath = GetResourcePath();
-    SkString filename = SkOSPath::SkPathJoin(resourcePath.c_str(), "mandrill_128.pkm");
+    SkString pkmFilename = GetResourcePath("mandrill_128.pkm");
 
     // Load PKM file into a bitmap
     SkBitmap etcBitmap;
-    SkAutoTUnref<SkData> fileData(SkData::NewFromFileName(filename.c_str()));
+    SkAutoTUnref<SkData> fileData(SkData::NewFromFileName(pkmFilename.c_str()));
     REPORTER_ASSERT(reporter, NULL != fileData);
 
     bool installDiscardablePixelRefSuccess =
@@ -161,7 +160,7 @@
     REPORTER_ASSERT(reporter, NULL != ktxDataPtr);
 
     // See is this data is identical to data in existing ktx file.
-    SkString ktxFilename = SkOSPath::SkPathJoin(resourcePath.c_str(), "mandrill_128.ktx");
+    SkString ktxFilename = GetResourcePath("mandrill_128.ktx");
     SkAutoDataUnref oldKtxData(SkData::NewFromFileName(ktxFilename.c_str()));
     REPORTER_ASSERT(reporter, oldKtxData->equals(newKtxData));
 }