Fix a crash in TemplateURLParser.

It was caused by dereferencing an invalid URL during parsing.

Bug: 770734
Change-Id: I4fedd3f310aaf7e1e1d2384aa64939d46b8b2a5a
Reviewed-on: https://chromium-review.googlesource.com/773902
Commit-Queue: Vasilii Sukhanov <vasilii@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517751}

chrome/browser/search_engines/template_url_parser_unittest.cc

@@ -245,3 +245,23 @@ TEST_F(TemplateURLParserTest, TestEmptyKeyword) {
             template_url_->url());
   EXPECT_EQ(ASCIIToUTF16("example.com"), template_url_->keyword());
 }
+
+// An invalid template URL should not crash the parser.
+// crbug.com/770734
+TEST_F(TemplateURLParserTest, InvalidInput) {
+  struct DumbFilter : TemplateURLParser::ParameterFilter {
+    bool KeepParameter(const std::string& key,
+                       const std::string& value) override {
+      return true;
+    }
+  } filter;
+  constexpr char char_data[] = R"(
+    <OpenSearchDescription>
+    <Url template=")R:RRR?>RRR0" type="application/x-suggestions+json">
+      <Param name="name" value="value"/>
+    </Url>
+    </OpenSearchDescription>
+  )";
+  TemplateURLParser::Parse(SearchTermsData(), char_data, arraysize(char_data),
+                           &filter);
+}

components/search_engines/template_url_parser.cc

@@ -438,7 +438,7 @@ void TemplateURLParsingContext::ProcessURLParams() {
     return;
 
   GURL url(is_suggest_url_ ? data_.suggestions_url : data_.url());
-  if (url.is_empty())
+  if (!url.is_valid())
     return;
 
   // If there is a parameter filter, parse the existing URL and remove any