Simplify skiatest framework.

tests/DocumentTest.cpp

Index: tests/DocumentTest.cpp
diff --git a/tests/DocumentTest.cpp b/tests/DocumentTest.cpp
index 97aefcb4e1b507c987833dcd3c6c70481faeba0c..62ba2378069fdeff1308c5fdec5b4ede50e86d65 100644
--- a/tests/DocumentTest.cpp
+++ b/tests/DocumentTest.cpp
@@ -29,7 +29,7 @@ static void test_abort(skiatest::Reporter* reporter) {
 }
 
 static void test_abortWithFile(skiatest::Reporter* reporter) {
-    SkString tmpDir = skiatest::Test::GetTmpDir();
+    SkString tmpDir = reporter->getTmpDir();
 
     if (tmpDir.isEmpty()) {
         return;  // TODO(edisonn): unfortunatelly this pattern is used in other
@@ -58,7 +58,7 @@ static void test_abortWithFile(skiatest::Reporter* reporter) {
 }
 
 static void test_file(skiatest::Reporter* reporter) {
-    SkString tmpDir = skiatest::Test::GetTmpDir();
+    SkString tmpDir = reporter->getTmpDir();
     if (tmpDir.isEmpty()) {
         return;  // TODO(edisonn): unfortunatelly this pattern is used in other
                  // tests, but if GetTmpDir() starts returning and empty dir