Adjust prefix path computations for base::Location

Make locations relative to the root of our own source tree.
---
 base/location.cc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/base/location.cc b/base/location.cc
index b38ec16beabb..552e774edc7b 100644
--- a/base/location.cc
+++ b/base/location.cc
@@ -31,11 +31,15 @@ constexpr size_t StrLen(const char* str) {
 constexpr size_t StrippedFilePathPrefixLength() {
   constexpr char path[] = __FILE__;
   // Only keep the file path starting from the src directory.
+#if defined(MOZ_ZUCCHINI)
+  constexpr char stripped[] = "third_party/zucchini/chromium/base/location.cc";
+#else
 #if defined(__clang__) && defined(_MSC_VER)
   constexpr char stripped[] = "base\\location.cc";
 #else
   constexpr char stripped[] = "base/location.cc";
 #endif
+#endif  // defined(MOZ_ZUCCHINI)
   constexpr size_t path_len = StrLen(path);
   constexpr size_t stripped_len = StrLen(stripped);
   static_assert(path_len >= stripped_len,
@@ -63,6 +67,10 @@ constexpr bool StrEndsWith(const char* name,
   return true;
 }
 
+#if defined(MOZ_ZUCCHINI)
+static_assert(StrEndsWith(__FILE__, kStrippedPrefixLength, "third_party/zucchini/chromium/base/location.cc"),
+              "The file name does not match the expected prefix format.");
+#else
 #if defined(__clang__) && defined(_MSC_VER)
 static_assert(StrEndsWith(__FILE__, kStrippedPrefixLength, "base\\location.cc"),
               "The file name does not match the expected prefix format.");
@@ -70,6 +78,7 @@ static_assert(StrEndsWith(__FILE__, kStrippedPrefixLength, "base\\location.cc"),
 static_assert(StrEndsWith(__FILE__, kStrippedPrefixLength, "base/location.cc"),
               "The file name does not match the expected prefix format.");
 #endif
+#endif  // defined(MOZ_ZUCCHINI)
 
 }  // namespace
 
-- 
2.42.0.windows.2