Offer user to send feedback from profile error dialog

components/history/core/browser/history_backend.h

Index: components/history/core/browser/history_backend.h
diff --git a/components/history/core/browser/history_backend.h b/components/history/core/browser/history_backend.h
index 0b952b4b4b8ac365694ec5fb0558123917c14526..aeecc96ab01663b118f0bcafaa8501c00f830d13 100644
--- a/components/history/core/browser/history_backend.h
+++ b/components/history/core/browser/history_backend.h
@@ -113,7 +113,10 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
     virtual ~Delegate() {}
 
     // Called when the database cannot be read correctly for some reason.
-    virtual void NotifyProfileError(sql::InitStatus init_status) = 0;
+    // |diagnostics| contains information about the underlying database
+    // which can help in identifying the cause of the profile error.
+    virtual void NotifyProfileError(sql::InitStatus init_status,
+                                    const std::string& diagnostics) = 0;
 
     // Sets the in-memory history backend. The in-memory backend is created by
     // the main backend. For non-unit tests, this happens on the background
@@ -879,6 +882,10 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
   // Listens for the system being under memory pressure.
   std::unique_ptr<base::MemoryPressureListener> memory_pressure_listener_;
 
+  // Contains diagnostic information about the sql database that is non-empty
+  // when a catastrophic error occurs.
+  std::string db_diagnostics_;
+
   // Map from host to index in the TopHosts list. It is updated only by
   // TopHosts(), so it's usually stale.
   mutable base::hash_map<std::string, int> host_ranks_;