[Chromecast] Do not upload dumps when directories don't exist.

This avoids a crash-on-first-boot on some emulators.

Bug: Internal b/138228866
Test: install apk on N emulator
Change-Id: Ieaf74fffcda20d96ffbc30c1180a137e0a970bbd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1715587Reviewed-by: Luke Halliwell <halliwell@chromium.org>
Commit-Queue: Simeon Anfinrud <sanfin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#680537}

chromecast/browser/cast_browser_main_parts.cc

@@ -638,9 +638,11 @@ void CastBrowserMainParts::StartPeriodicCrashReportUpload() {
 
 void CastBrowserMainParts::OnStartPeriodicCrashReportUpload() {
   base::FilePath crash_dir;
-  CrashHandler::GetCrashDumpLocation(&crash_dir);
+  if (!CrashHandler::GetCrashDumpLocation(&crash_dir))
+    return;
   base::FilePath reports_dir;
-  CrashHandler::GetCrashReportsLocation(&reports_dir);
+  if (!CrashHandler::GetCrashReportsLocation(&reports_dir))
+    return;
   CrashHandler::UploadDumps(crash_dir, reports_dir, "", "");
 }
 #endif  // defined(OS_ANDROID)