Log messages regarding why app banners aren't displayed to the console

chrome/browser/banners/app_banner_data_fetcher_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/banners/app_banner_data_fetcher.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace banners {
@@ skipping 15 matching lines @@
 
     content::Manifest::Icon icon;
     icon.type = ToNullableUTF16("image/png");
     icon.sizes.push_back(gfx::Size(144, 144));
     manifest.icons.push_back(icon);
 
     return manifest;
   }
 
   static bool IsManifestValid(const content::Manifest& manifest) {
-    return AppBannerDataFetcher::IsManifestValidForWebApp(manifest);
+    // The second argument is the web_contents pointer, which is used for
+    // developer debug logging to the console. The logging is skipped inside the
+    // method if a null web_contents pointer is provided, so this is safe.
+    return AppBannerDataFetcher::IsManifestValidForWebApp(manifest, nullptr);
   }
 };
 
 TEST_F(AppBannerDataFetcherUnitTest, EmptyManifestIsInvalid) {
   content::Manifest manifest;
   EXPECT_FALSE(IsManifestValid(manifest));
 }
 
 TEST_F(AppBannerDataFetcherUnitTest, CheckMinimalValidManifest) {
   content::Manifest manifest = GetValidManifest();
@@ skipping 51 matching lines @@
   // Non-square is okay.
   manifest.icons[0].sizes[1] = gfx::Size(144, 200);
   EXPECT_TRUE(IsManifestValid(manifest));
 
   // The representation of the keyword 'any' should be recognized.
   manifest.icons[0].sizes[1] = gfx::Size(0, 0);
   EXPECT_TRUE(IsManifestValid(manifest));
 }
 
 }  // namespace banners