Expose GetLoggingFileName in ContentBrowserClient.

content/public/browser/content_browser_client.h

Index: content/public/browser/content_browser_client.h
diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
index e58f1099eba8054b37136f46854907fe59353b47..c092dce658aad9dfdeab4164bd80322dd23f7ce2 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -320,6 +320,9 @@ class CONTENT_EXPORT ContentBrowserClient {
   // Returns the default favicon.  The callee doesn't own the given bitmap.
   virtual const gfx::ImageSkia* GetDefaultFavicon();
 
+  // Returns the fully qualified path to the log file name, or an empty path.

[Charlie Reis, 2017/06/06 17:14:10]

Might be worth mentioning why this is useful (e.g., so sandbox can make it
available, presumably?).  Otherwise people may think they should write to it
directly.

[Greg K, 2017/06/06 17:18:17]

Done.

+  virtual base::FilePath GetLoggingFileName();
+
   // Allow the embedder to control if an AppCache can be used for the given url.
   // This is called on the IO thread.
   virtual bool AllowAppCache(const GURL& manifest_url,