Add tests for IgnoreResult() receiving a callback.

Also test that it can IgnoreResult a callback with arguments and the
resulting callback will still accept those arguments.

R=dcheng@chromium.org

Bug: 1140582
Change-Id: If01cd5442f1ef0185fce74f6952cbdf54aaef07a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2503769Reviewed-by: Gabriel Charette <gab@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821355}

base/bind_unittest.cc

@@ -13,6 +13,7 @@
 #include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/test/bind_test_util.h"
 #include "base/test/gtest_util.h"
 #include "build/build_config.h"
@@ -513,6 +514,32 @@ TEST_F(BindTest, IgnoreResultForOnce) {
   std::move(non_void_weak_method_cb).Run();
 }
 
+TEST_F(BindTest, IgnoreResultForRepeatingCallback) {
+  std::string s;
+  RepeatingCallback<int(int)> cb = BindRepeating(
+      [](std::string* s, int i) {
+        *s += "Run" + base::NumberToString(i);
+        return 5;
+      },
+      &s);
+  RepeatingCallback<void(int)> noreturn = BindRepeating(IgnoreResult(cb));
+  noreturn.Run(2);
+  EXPECT_EQ(s, "Run2");
+}
+
+TEST_F(BindTest, IgnoreResultForOnceCallback) {
+  std::string s;
+  OnceCallback<int(int)> cb = BindOnce(
+      [](std::string* s, int i) {
+        *s += "Run" + base::NumberToString(i);
+        return 5;
+      },
+      &s);
+  OnceCallback<void(int)> noreturn = BindOnce(IgnoreResult(std::move(cb)));
+  std::move(noreturn).Run(2);
+  EXPECT_EQ(s, "Run2");
+}
+
 // Functions that take reference parameters.
 //  - Forced reference parameter type still stores a copy.
 //  - Forced const reference parameter type still stores a copy.