Revert of Eliminate silently letting errors pass on pak loading.

ui/base/resource/resource_bundle_unittest.cc

Index: ui/base/resource/resource_bundle_unittest.cc
diff --git a/ui/base/resource/resource_bundle_unittest.cc b/ui/base/resource/resource_bundle_unittest.cc
index 11a886654155f7045ea9e6bc37169d4a3380b76a..488947dbc8f8be5bb1067e830662b3c5b900d624 100644
--- a/ui/base/resource/resource_bundle_unittest.cc
+++ b/ui/base/resource/resource_bundle_unittest.cc
@@ -186,7 +186,7 @@
           Property(&base::FilePath::value, pack_path.value()),
           pack_scale_factor))
       .Times(1)
-      .WillOnce(Return(base::FilePath()));
+      .WillOnce(Return(pack_path));
 
   resource_bundle->AddDataPackFromPath(pack_path, pack_scale_factor);
 }
@@ -414,6 +414,7 @@
 };
 
 // Verify that we don't crash when trying to load a resource that is not found.
+// In some cases, we fail to mmap resources.pak, but try to keep going anyway.
 TEST_F(ResourceBundleImageTest, LoadDataResourceBytes) {
   base::FilePath data_path = dir_path().Append(FILE_PATH_LITERAL("sample.pak"));
 
@@ -426,6 +427,13 @@
   resource_bundle->AddDataPackFromPath(data_path, SCALE_FACTOR_100P);
 
   const int kUnfoundResourceId = 10000;
+  EXPECT_EQ(NULL, resource_bundle->LoadDataResourceBytes(
+      kUnfoundResourceId));
+
+  // Give a .pak file that doesn't exist so we will fail to load it.
+  resource_bundle->AddDataPackFromPath(
+      base::FilePath(FILE_PATH_LITERAL("non-existant-file.pak")),
+      ui::SCALE_FACTOR_NONE);
   EXPECT_EQ(NULL, resource_bundle->LoadDataResourceBytes(
       kUnfoundResourceId));
 }