Convert ARRAYSIZE_UNSAFE -> arraysize.

Source/core/loader/MixedContentCheckerTest.cpp

Index: Source/core/loader/MixedContentCheckerTest.cpp
diff --git a/Source/core/loader/MixedContentCheckerTest.cpp b/Source/core/loader/MixedContentCheckerTest.cpp
index 903bc2f80cc66ce7ed0b54952f871dba966b3f89..a9f156b67d651983f63df1c95e7efbf20ce8e6af 100644
--- a/Source/core/loader/MixedContentCheckerTest.cpp
+++ b/Source/core/loader/MixedContentCheckerTest.cpp
@@ -31,7 +31,7 @@ TEST(MixedContentCheckerTest, IsMixedContent)
         {"https://example.com/foo", "ws://google.com/foo", true},
     };
 
-    for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
+    for (size_t i = 0; i < arraysize(cases); ++i) {
         const char* origin = cases[i].origin;
         const char* target = cases[i].target;
         bool expectation = cases[i].expectation;