Add UMA histogram to see how widespread it is for users to have a favicons database with a missing column.

Bug=151841, 160360
Test=histogram for ThumbnailDatabase.InvalidFaviconsDBStructure shows up on histograms dashboard

Review URL: https://chromiumcodereview.appspot.com/11362191

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@167327 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 18 insertions, 0 deletions

diff --git a/chrome/browser/history/thumbnail_database.cc b/chrome/browser/history/thumbnail_database.cc
index f0e45f9..d4d1b5a 100644
--- a/chrome/browser/history/thumbnail_database.cc
+++ b/chrome/browser/history/thumbnail_database.cc
@@ -10,6 +10,7 @@
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/memory/ref_counted_memory.h"
+#include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
 #include "base/string_tokenizer.h"
 #include "base/string_util.h"
@@ -197,6 +198,10 @@ sql::InitStatus ThumbnailDatabase::Init(
     return sql::INIT_FAILURE;
   }
 
+  // Log in a UMA histogram if the structure of the favicons database is not
+  // what it should be.
+  LogIfFaviconDBStructureIncorrect();
+
   return sql::INIT_OK;
 }
 
@@ -321,6 +326,11 @@ bool ThumbnailDatabase::InitFaviconBitmapsIndex() {
                      "favicon_bitmaps(icon_id)");
 }
 
+void ThumbnailDatabase::LogIfFaviconDBStructureIncorrect() {
+  if (!db_.IsSQLValid("SELECT id, url, icon_type, sizes FROM favicons"))
+    UMA_HISTOGRAM_BOOLEAN("ThumbnailDatabase.InvalidFaviconsDBStructure", true);
+}
+
 void ThumbnailDatabase::BeginTransaction() {
   db_.BeginTransaction();
 }
diff --git a/chrome/browser/history/thumbnail_database.h b/chrome/browser/history/thumbnail_database.h
index c9f4dc8..c6f2208 100644
--- a/chrome/browser/history/thumbnail_database.h
+++ b/chrome/browser/history/thumbnail_database.h
@@ -376,6 +376,14 @@ class ThumbnailDatabase {
   // with no index).
   bool InitIconMappingIndex();
 
+  // For the purpose of determining how widespread www.crbug.com/151841 is, log
+  // in a UMA histogram if the |favicons| database is missing a column. This is
+  // important because the SQLite error code from running SQL statements against
+  // a database with missing columns is SQLITE_ERROR which is not unique enough
+  // to act upon.
+  // TODO(pkotwicz): remove this function once www.crbug.com/151841 is resolved.
+  void LogIfFaviconDBStructureIncorrect();
+
   // Adds a mapping between the given page_url and icon_id; The mapping will be
   // added to temp_icon_mapping table if is_temporary is true.
   // Returns the new mapping id if the adding succeeds, otherwise 0 is returned.