headless: Add support for minidump generation on Linux

headless/lib/browser/headless_content_browser_client.h

Index: headless/lib/browser/headless_content_browser_client.h
diff --git a/headless/lib/browser/headless_content_browser_client.h b/headless/lib/browser/headless_content_browser_client.h
index 202219f3867509ccca834b1bd3f2ed4ae6f8d231..aa18883250c9c2b3bf8394004e2db310177647a9 100644
--- a/headless/lib/browser/headless_content_browser_client.h
+++ b/headless/lib/browser/headless_content_browser_client.h
@@ -28,6 +28,12 @@ class HeadlessContentBrowserClient : public content::ContentBrowserClient {
       content::BrowserContext* context,
       content::StoragePartition* partition,
       const storage::OptionalQuotaSettingsCallback& callback) override;
+  void GetAdditionalMappedFilesForChildProcess(
+      const base::CommandLine& command_line,
+      int child_process_id,
+      content::FileDescriptorInfo* mappings) override;
+  void AppendExtraCommandLineSwitches(base::CommandLine* command_line,
+                                      int child_process_id) override;
 
  private:
   HeadlessBrowserImpl* browser_;  // Not owned.