Fixing data inconsistency problem with lovefield/indexeddb. There is …

…currently the possibility for a bad transaction when you are trying to replace a row, in a single row object store.

The problem manifests as follows
- have a single row in an object store
- do a transaction that deletes the row, and then inserts a new row
- observe that in the end, no rows exist.

The way this happens is that the lovefield journal flushing code allows its delete and put calls to race (i.e. not promise chained). Delete has a special optimization where it counts the number of rows in the table, and if the number of IDS to delete == the number of rows that exist, then it just clears the table. For the case of single row delete/insert, the following sequence can happen with the race.
1. delete code counts number of rows that exist (returns 1)
2. put happens (now number of rows == 2)
3. chained from 1, objectStore.clear() is called (removes 2 instead of 1)

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=171225366

dist/lovefield.js

@@ -503,10 +503,14 @@ goog.globalEval = function(script) {
   } else {
     if (goog.global.eval) {
       if (null == goog.evalWorksForGlobals_) {
-        if (goog.global.eval("var _evalTest_ = 1;"), "undefined" != typeof goog.global._evalTest_) {
+        try {
+          goog.global.eval("var _evalTest_ = 1;");
+        } catch (ignore) {
+        }
+        if ("undefined" != typeof goog.global._evalTest_) {
           try {
             delete goog.global._evalTest_;
-          } catch (ignore) {
+          } catch (ignore$0) {
           }
           goog.evalWorksForGlobals_ = !0;
         } else {
@@ -520,8 +524,8 @@ goog.globalEval = function(script) {
         scriptElt.type = "text/javascript";
         scriptElt.defer = !1;
         scriptElt.appendChild(doc.createTextNode(script));
-        doc.body.appendChild(scriptElt);
-        doc.body.removeChild(scriptElt);
+        doc.head.appendChild(scriptElt);
+        doc.head.removeChild(scriptElt);
       }
     } else {
       throw Error("goog.globalEval not available");
@@ -1194,6 +1198,10 @@ goog.asserts.assertInstanceof = function(value, type, opt_message, var_args) {
   !goog.asserts.ENABLE_ASSERTS || value instanceof type || goog.asserts.doAssertFailure_("Expected instanceof %s but got %s.", [goog.asserts.getType_(type), goog.asserts.getType_(value)], opt_message, Array.prototype.slice.call(arguments, 3));
   return value;
 };
+goog.asserts.assertFinite = function(value, opt_message, var_args) {
+  !goog.asserts.ENABLE_ASSERTS || "number" == typeof value && isFinite(value) || goog.asserts.doAssertFailure_("Expected %s to be a finite number but it is not.", [value], opt_message, Array.prototype.slice.call(arguments, 2));
+  return value;
+};
 goog.asserts.assertObjectPrototypeIsIntact = function() {
   for (var key in Object.prototype) {
     goog.asserts.fail(key + " should not be enumerable in Object.prototype.");
@@ -3072,9 +3080,9 @@ goog.iter.forEach = function(iterable, f, opt_obj) {
       for (;;) {
         f.call(opt_obj, iterable.next(), void 0, iterable);
       }
-    } catch (ex$0) {
-      if (ex$0 !== goog.iter.StopIteration) {
-        throw ex$0;
+    } catch (ex$1) {
+      if (ex$1 !== goog.iter.StopIteration) {
+        throw ex$1;
       }
     }
   }
@@ -3786,10 +3794,10 @@ goog.userAgent.isDocumentModeOrHigher = function(documentMode) {
   return Number(goog.userAgent.DOCUMENT_MODE) >= documentMode;
 };
 goog.userAgent.isDocumentMode = goog.userAgent.isDocumentModeOrHigher;
-var JSCompiler_inline_result$jscomp$1;
-var doc$jscomp$inline_3 = goog.global.document, mode$jscomp$inline_4 = goog.userAgent.getDocumentMode_();
-JSCompiler_inline_result$jscomp$1 = doc$jscomp$inline_3 && goog.userAgent.IE ? mode$jscomp$inline_4 || ("CSS1Compat" == doc$jscomp$inline_3.compatMode ? parseInt(goog.userAgent.VERSION, 10) : 5) : void 0;
-goog.userAgent.DOCUMENT_MODE = JSCompiler_inline_result$jscomp$1;
+var JSCompiler_inline_result$jscomp$2;
+var doc$jscomp$inline_4 = goog.global.document, mode$jscomp$inline_5 = goog.userAgent.getDocumentMode_();
+JSCompiler_inline_result$jscomp$2 = doc$jscomp$inline_4 && goog.userAgent.IE ? mode$jscomp$inline_5 || ("CSS1Compat" == doc$jscomp$inline_4.compatMode ? parseInt(goog.userAgent.VERSION, 10) : 5) : void 0;
+goog.userAgent.DOCUMENT_MODE = JSCompiler_inline_result$jscomp$2;
 goog.userAgent.platform = {};
 goog.userAgent.platform.determineVersion_ = function() {
   if (goog.userAgent.WINDOWS) {
@@ -4069,11 +4077,10 @@ lf.backstore.BaseTx.prototype.mergeTableChanges_ = function() {
   diff.forEach(function(tableDiff, tableName) {
     var tableSchema = this.journal_.getScope().get(tableName), table = this.getTable(tableSchema.getName(), tableSchema.deserializeRow.bind(tableSchema), lf.backstore.TableType.DATA), toDeleteRowIds = lf.structs.map.values(tableDiff.deleted_).map(function(row) {
       return row.id();
-    });
-    0 < toDeleteRowIds.length && table.remove(toDeleteRowIds).thenCatch(this.handleError_, this);
-    var toPut = lf.structs.map.values(tableDiff.modified_).map(function(modification) {
+    }), toPut = lf.structs.map.values(tableDiff.modified_).map(function(modification) {
       return modification[1];
-    }).concat(lf.structs.map.values(tableDiff.added_));
+    }).concat(lf.structs.map.values(tableDiff.added_)), shouldDisableClearTableOptimization = 0 < toPut.length;
+    0 < toDeleteRowIds.length && table.remove(toDeleteRowIds, shouldDisableClearTableOptimization).thenCatch(this.handleError_, this);
     table.put(toPut).thenCatch(this.handleError_, this);
   }, this);
 };
@@ -6557,24 +6564,24 @@ lf.backstore.ObjectStore.prototype.put = function(rows) {
   }, this);
   return goog.Promise.all(promises);
 };
-lf.backstore.ObjectStore.prototype.remove = function(ids) {
-  return new goog.Promise(function(resolve, reject) {
-    var request = this.store_.count();
+lf.backstore.ObjectStore.prototype.remove = function(ids, disableClearTableOptimization) {
+  var $jscomp$this = this, deleteByIdsFn = function() {
+    var promises = ids.map(function(id) {
+      return $jscomp$this.performWriteOp_(function() {
+        return $jscomp$this.store_.delete(id);
+      });
+    });
+    return goog.Promise.all(promises);
+  };
+  return disableClearTableOptimization ? deleteByIdsFn() : new goog.Promise(function(resolve, reject) {
+    var request = $jscomp$this.store_.count();
     request.onsuccess = function(ev) {
-      if (0 == ids.length || ev.target.result == ids.length) {
-        return this.performWriteOp_(function() {
-          return this.store_.clear();
-        }.bind(this)).then(resolve, reject);
-      }
-      var promises = ids.map(function(id) {
-        return this.performWriteOp_(function() {
-          return this.store_.delete(id);
-        }.bind(this));
-      }, this);
-      goog.Promise.all(promises).then(resolve, reject);
-    }.bind(this);
+      0 == ids.length || ev.target.result == ids.length ? $jscomp$this.performWriteOp_(function() {
+        return $jscomp$this.store_.clear();
+      }).then(resolve, reject) : deleteByIdsFn().then(resolve, reject);
+    };
     request.onerror = reject;
-  }, this);
+  });
 };
 lf.backstore.IndexedDBTx = function(global, transaction, txType, bundleMode, opt_journal) {
   lf.backstore.BaseTx.call(this, txType, opt_journal);