Disable ResourceBundleImageTest.FallbackToNone on iOS.

ui/base/resource/resource_bundle_unittest.cc

 // Copyright (c) 2012 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 "ui/base/resource/resource_bundle.h"
 
 #include "base/base_paths.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
@@ skipping 544 matching lines @@
   gfx::ImageSkiaRep image_rep =
     image_skia->GetRepresentation(
       GetImageScale(ui::SCALE_FACTOR_140P));
   EXPECT_EQ(12, image_rep.pixel_width());
   image_rep = image_skia->GetRepresentation(
     GetImageScale(ui::SCALE_FACTOR_180P));
   EXPECT_EQ(15, image_rep.pixel_width());
 }
 #endif
 
-TEST_F(ResourceBundleImageTest, FallbackToNone) {
+#if defined(OS_IOS)
+// Fails on devices that have non-100P scaling. See crbug.com/298406
+#define MAYBE_FallbackToNone DISABLED_FallbackToNone
+#else
+#define MAYBE_FallbackToNone FallbackToNone
+#endif
+TEST_F(ResourceBundleImageTest, MAYBE_FallbackToNone) {
   base::FilePath data_default_path = dir_path().AppendASCII("sample.pak");
 
   // Create the pak files.
   CreateDataPackWithSingleBitmap(data_default_path, 10, base::StringPiece());
 
     // Load the regular pak files only.
   ResourceBundle* resource_bundle = CreateResourceBundleWithEmptyLocalePak();
   resource_bundle->AddDataPackFromPath(data_default_path, SCALE_FACTOR_NONE);
 
   gfx::ImageSkia* image_skia = resource_bundle->GetImageSkiaNamed(3);
   EXPECT_EQ(1u, image_skia->image_reps().size());
   EXPECT_EQ(ui::SCALE_FACTOR_100P,
             GetSupportedScaleFactor(image_skia->image_reps()[0].scale()));
 }
 
 }  // namespace ui