Refactor clearing thumbnail history.

Previously, ThumbnailDatabase exposed much internals knowledge.  Push
most of that down into the class and remove the schema hacks which are
no longer necessary.

BUG=272519
TEST=Unit tests.

Review URL: https://chromiumcodereview.appspot.com/22898003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@217993 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 28 insertions, 0 deletions

diff --git a/sql/connection.cc b/sql/connection.cc
index 3bc2545..097edd7 100644
--- a/sql/connection.cc
+++ b/sql/connection.cc
@@ -724,6 +724,29 @@ scoped_refptr<Connection::StatementRef> Connection::GetUntrackedStatement(
   return new StatementRef(NULL, stmt, true);
 }
 
+std::string Connection::GetSchema() const {
+  // The ORDER BY should not be necessary, but relying on organic
+  // order for something like this is questionable.
+  const char* kSql =
+      "SELECT type, name, tbl_name, sql "
+      "FROM sqlite_master ORDER BY 1, 2, 3, 4";
+  Statement statement(GetUntrackedStatement(kSql));
+
+  std::string schema;
+  while (statement.Step()) {
+    schema += statement.ColumnString(0);
+    schema += '|';
+    schema += statement.ColumnString(1);
+    schema += '|';
+    schema += statement.ColumnString(2);
+    schema += '|';
+    schema += statement.ColumnString(3);
+    schema += '\n';
+  }
+
+  return schema;
+}
+
 bool Connection::IsSQLValid(const char* sql) {
   AssertIOAllowed();
   if (!db_) {
diff --git a/sql/connection.h b/sql/connection.h
index 24f06de..7938606 100644
--- a/sql/connection.h
+++ b/sql/connection.h
@@ -389,6 +389,11 @@ class SQL_EXPORT Connection {
   // last sqlite operation.
   const char* GetErrorMessage() const;
 
+  // Return a reproducible representation of the schema equivalent to
+  // running the following statement at a sqlite3 command-line:
+  //   SELECT type, name, tbl_name, sql FROM sqlite_master ORDER BY 1, 2, 3, 4;
+  std::string GetSchema() const;
+
  private:
   // For recovery module.
   friend class Recovery;