[sql] Track uploads of diagnostic data to prevent duplication.

sql/connection.h

Index: sql/connection.h
diff --git a/sql/connection.h b/sql/connection.h
index 7d2ab6a355bfc9d448f4f58fd18480b2e3d1d722..fa36a002e298f2e1c4c5d9a3834744a35e0b2377 100644
--- a/sql/connection.h
+++ b/sql/connection.h
@@ -470,6 +470,23 @@ class SQL_EXPORT Connection : public base::trace_event::MemoryDumpProvider {
       const base::trace_event::MemoryDumpArgs& args,
       base::trace_event::ProcessMemoryDump* process_memory_dump) override;
 
+  // Helper to prevent uploading too many diagnostic dumps for a given database,
+  // since every dump will likely show the same problem.  Returns |true| if this
+  // function was not previously called for this database, and the persistent
+  // storage which tracks state was updated.
+  //
+  // |false| is returned if the function was previously called for this
+  // database, even across restarts.  |false| is also returned if the persistent
+  // storage cannot be updated, possibly indicating problems requiring user or
+  // admin intervention, such as filesystem corruption or disk full.  |false| is
+  // also returned if the persistent storage contains invalid data or is not
+  // readable.
+  //
+  // TODO(shess): It would make sense to reset the persistent state if the
+  // database is razed or recovered, or if the diagnostic code adds new
+  // capabilities.
+  bool RegisterIntentToUpload() const;
+
  private:
   // For recovery module.
   friend class Recovery;
@@ -504,7 +521,7 @@ class SQL_EXPORT Connection : public base::trace_event::MemoryDumpProvider {
   // Check whether the current thread is allowed to make IO calls, but only
   // if database wasn't open in memory. Function is inlined to be a no-op in
   // official build.
-  void AssertIOAllowed() {
+  void AssertIOAllowed() const {
     if (!in_memory_)
       base::ThreadRestrictions::AssertIOAllowed();
   }
@@ -653,6 +670,10 @@ class SQL_EXPORT Connection : public base::trace_event::MemoryDumpProvider {
   // which do not participate in the total-rows-changed tracking.
   void ReleaseCacheMemoryIfNeeded(bool implicit_change_performed);
 
+  // Returns the results of sqlite3_db_filename(), which should match the path
+  // passed to Open().
+  base::FilePath DbPath() const;
+
   // The actual sqlite database. Will be NULL before Init has been called or if
   // Init resulted in an error.
   sqlite3* db_;