Double-check safe-browsing database validity on update failure.

chrome/browser/safe_browsing/safe_browsing_store_file.h

Index: chrome/browser/safe_browsing/safe_browsing_store_file.h
diff --git a/chrome/browser/safe_browsing/safe_browsing_store_file.h b/chrome/browser/safe_browsing/safe_browsing_store_file.h
index d4e4403a03256f4698bfc4a35e205c77552e4221..e0baf12b8a28d3bd8ef5cc936aaa86f607630671 100644
--- a/chrome/browser/safe_browsing/safe_browsing_store_file.h
+++ b/chrome/browser/safe_browsing/safe_browsing_store_file.h
@@ -153,6 +153,10 @@ class SafeBrowsingStoreFile : public SafeBrowsingStore {
   virtual void DeleteAddChunk(int32 chunk_id) OVERRIDE;
   virtual void DeleteSubChunk(int32 chunk_id) OVERRIDE;
 
+  // Verify |file_|'s checksum, calling the corruption callback if it
+  // does not check out.  Empty input is considered valid.
+  virtual bool CheckValidity() OVERRIDE;
+
   // Returns the name of the temporary file used to buffer data for
   // |filename|.  Exported for unit tests.
   static const FilePath TemporaryFileForFilename(const FilePath& filename) {
@@ -190,6 +194,12 @@ class SafeBrowsingStoreFile : public SafeBrowsingStore {
     FORMAT_EVENT_DELETED_ORIGINAL,
     FORMAT_EVENT_DELETED_ORIGINAL_FAILED,
 
+    // The checksum did not check out in CheckValidity() or in
+    // FinishUpdate().  This most likely indicates that the machine
+    // crashed before the file was fully sync'ed to disk.
+    FORMAT_EVENT_VALIDITY_CHECKSUM_FAILURE,
+    FORMAT_EVENT_UPDATE_CHECKSUM_FAILURE,
+
     // Memory space for histograms is determined by the max.  ALWAYS
     // ADD NEW VALUES BEFORE THIS ONE.
     FORMAT_EVENT_MAX