Original patch from issue 570048

chrome/renderer/resources/json_schema.js

Index: chrome/renderer/resources/json_schema.js
diff --git a/chrome/renderer/resources/json_schema.js b/chrome/renderer/resources/json_schema.js
index ff1c0a067a35222bbd61769ba86ba5df0571b91b..f5d632a41a02a38f9bbb044303ee99d51a194287 100644
--- a/chrome/renderer/resources/json_schema.js
+++ b/chrome/renderer/resources/json_schema.js
@@ -405,14 +405,16 @@ chromeHidden.JSONSchemaValidator.prototype.validateNumber = function(
       instance == Number.NEGATIVE_INFINITY )
     this.addError(path, "numberFiniteNotNan", [instance]);
 
-  if (schema.minimum && instance < schema.minimum)
+  if (typeof schema.minimum != 'undefined' && instance < schema.minimum)
     this.addError(path, "numberMinValue", [schema.minimum]);
 
-  if (schema.maximum && instance > schema.maximum)
+  if (typeof schema.maximum != 'undefined' && instance > schema.maximum)
     this.addError(path, "numberMaxValue", [schema.maximum]);
 
-  if (schema.maxDecimal && instance * Math.pow(10, schema.maxDecimal) % 1)
+  if (typeof schema.maxDecimal != 'undefined' &&
+      instance * Math.pow(10, schema.maxDecimal) % 1) {
     this.addError(path, "numberMaxDecimal", [schema.maxDecimal]);
+  }
 };
 
 /**