Overload stream insertion for DawnTestParam

Passing "--gtest_list_tests" as an argument to the gtest binary lists
the tests in the binary. However, when the test suite is parameterized
(like in the case of dawn_end2end_tests), the output will list the
string name of the parameter along with the test name. Since there is no
stream insertion overload for DawnTestParam, we get this output:

./dawn_end2end_tests --gtest_list_tests
BasicTests.
  BufferSetSubData/OpenGL  # GetParam() = 56-byte object <03-00 00-00 19...
  BufferSetSubData/Vulkan  # GetParam() = 56-byte object <04-00 00-00 19...
  ...

This CL adds an implementation to display the string name of the param
instead.

BUG=chromium:993457
TEST=run ./dawn_end2end_test --gtest_list_tests

Change-Id: Ifae65a9eaf96448341e6ed1894f116f1af1154b7
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/10240
Commit-Queue: Brian Ho <hob@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>

src/tests/DawnTest.cpp

diff --git a/src/tests/DawnTest.cpp b/src/tests/DawnTest.cpp
index 938c9434..41902a4 100644
--- a/src/tests/DawnTest.cpp
+++ b/src/tests/DawnTest.cpp
@@ -93,6 +93,17 @@
     return newTestParam;
 }
 
+std::ostream& operator<<(std::ostream& os, const DawnTestParam& param) {
+    os << ParamName(param.backendType);
+    for (const char* forceEnabledWorkaround : param.forceEnabledWorkarounds) {
+        os << "__e_" << forceEnabledWorkaround;
+    }
+    for (const char* forceDisabledWorkaround : param.forceDisabledWorkarounds) {
+        os << "__d_" << forceDisabledWorkaround;
+    }
+    return os;
+}
+
 // Implementation of DawnTestEnvironment
 
 void InitDawnEnd2EndTestEnvironment(int argc, char** argv) {
@@ -710,17 +721,6 @@
         return backends;
     }
 
-    std::string GetParamName(const testing::TestParamInfo<DawnTestParam>& info) {
-        std::ostringstream ostream;
-        ostream << ParamName(info.param.backendType);
-
-        for (const char* forceEnabledWorkaround : info.param.forceEnabledWorkarounds) {
-            ostream << "_" << forceEnabledWorkaround;
-        }
-
-        return ostream.str();
-    }
-
     // Helper classes to set expectations
 
     template <typename T>

src/tests/DawnTest.h

diff --git a/src/tests/DawnTest.h b/src/tests/DawnTest.h
index 34a0669..4633716 100644
--- a/src/tests/DawnTest.h
+++ b/src/tests/DawnTest.h
@@ -83,6 +83,8 @@
     std::vector<const char*> forceDisabledWorkarounds;
 };
 
+std::ostream& operator<<(std::ostream& os, const DawnTestParam& param);
+
 // Shorthands for backend types used in the DAWN_INSTANTIATE_TEST
 extern const DawnTestParam D3D12Backend;
 extern const DawnTestParam MetalBackend;
@@ -269,7 +271,7 @@
         , testName,                                                              \
         testing::ValuesIn(::detail::FilterBackends(                              \
             testName##params, sizeof(testName##params) / sizeof(firstParam))),   \
-        ::detail::GetParamName)
+        testing::PrintToStringParamName())
 
 // Skip a test when the given condition is satisfied.
 #define DAWN_SKIP_TEST_IF(condition)                               \
@@ -282,7 +284,6 @@
     // Helper functions used for DAWN_INSTANTIATE_TEST
     bool IsBackendAvailable(dawn_native::BackendType type);
     std::vector<DawnTestParam> FilterBackends(const DawnTestParam* params, size_t numParams);
-    std::string GetParamName(const testing::TestParamInfo<DawnTestParam>& info);
 
     // All classes used to implement the deferred expectations should inherit from this.
     class Expectation {