Bug 1318091 - Support env override of gtest minidump location; r=Ehsan

Desktop gtest creates minidumps in the current working directory. That is
problematic on Android, since the test app's cwd may not be writable, or
may not be readable by the test harness. This patch allows the test harness
to specify an alternate minidump path with environment variable
MOZ_GTEST_MINIDUMPS_PATH.

Differential Revision: https://phabricator.services.mozilla.com/D26833

--HG--
extra : moz-landing-system : lando

testing/gtest/mozilla/GTestRunner.cpp

@@ -121,16 +121,25 @@ int RunGTestFunc(int* argc, char** argv) {
     // C++ unittests
     crashreporter = do_GetService("@mozilla.org/toolkit/crash-reporter;1");
     if (crashreporter) {
-      std::cerr << "Setting up crash reporting" << std::endl;
-
-      nsCOMPtr<nsIProperties> dirsvc =
-          do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID);
-      nsCOMPtr<nsIFile> cwd;
-      nsresult rv = dirsvc->Get(NS_OS_CURRENT_WORKING_DIR, NS_GET_IID(nsIFile),
-                                getter_AddRefs(cwd));
-      MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
+      printf_stderr("Setting up crash reporting\n");
+      char* path = PR_GetEnv("MOZ_GTEST_MINIDUMPS_PATH");
+      nsCOMPtr<nsIFile> file;
+      if (path) {
+        nsresult rv = NS_NewLocalFile(NS_ConvertUTF8toUTF16(path), true,
+                                      getter_AddRefs(file));
+        if (NS_FAILED(rv)) {
+          printf_stderr("Ignoring invalid MOZ_GTEST_MINIDUMPS_PATH\n");
+        }
+      }
+      if (!file) {
+        nsCOMPtr<nsIProperties> dirsvc =
+            do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID);
+        nsresult rv = dirsvc->Get(NS_OS_CURRENT_WORKING_DIR, NS_GET_IID(nsIFile),
+                                  getter_AddRefs(file));
+        MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
+      }
       crashreporter->SetEnabled(true);
-      crashreporter->SetMinidumpPath(cwd);
+      crashreporter->SetMinidumpPath(file);
     }
   }