DM: Add support for reading a directory of images with --expectations (-r).

dm/DM.cpp

Index: dm/DM.cpp
diff --git a/dm/DM.cpp b/dm/DM.cpp
index 274ec2a815eb89f8aa6ab40d478da116f9df9050..65fccc761177893b1f1f49609533c076f0e7fb36 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -14,18 +14,18 @@
 #include "DMTaskRunner.h"
 #include "DMCpuTask.h"
 #include "DMGpuTask.h"
+#include "DMWriteTask.h"
 
 #include <string.h>
 
 using skiagm::GM;
 using skiagm::GMRegistry;
-using skiagm::Expectations;
-using skiagm::ExpectationsSource;
-using skiagm::JsonExpectationsSource;
 
 DEFINE_int32(cpuThreads, -1, "Threads for CPU work. Default NUM_CPUS.");
 DEFINE_int32(gpuThreads, 1, "Threads for GPU work.");
-DEFINE_string(expectations, "", "Compare generated images against JSON expectations at this path.");
+DEFINE_string2(expectations, r, "",
+               "If a directory, compare generated images against images under this path. "
+               "If a file, compare generated images against JSON expectations at this path.");
 DEFINE_string(resources, "resources", "Path to resources directory.");
 DEFINE_string(match, "",  "[~][^]substring[$] [...] of GM name to run.\n"
                           "Multiple matches may be separated by spaces.\n"
@@ -50,7 +50,7 @@ static SkString lowercase(SkString s) {
 
 static void kick_off_tasks(const SkTDArray<GMRegistry::Factory>& gms,
                            const SkTArray<SkString>& configs,
-                           const ExpectationsSource& expectations,
+                           const DM::Expectations& expectations,
                            DM::Reporter* reporter,
                            DM::TaskRunner* tasks) {
     const SkBitmap::Config _565 = SkBitmap::kRGB_565_Config;
@@ -107,13 +107,6 @@ static void report_failures(const DM::Reporter& reporter) {
     }
 }
 
-class NoExpectations : public ExpectationsSource {
-public:
-    Expectations get(const char* /*testName*/) const SK_OVERRIDE {
-        return Expectations();
-    }
-};
-
 int tool_main(int argc, char** argv);
 int tool_main(int argc, char** argv) {
     SkGraphics::Init();
@@ -134,9 +127,14 @@ int tool_main(int argc, char** argv) {
     }
     SkDebugf("%d GMs x %d configs\n", gms.count(), configs.count());
 
-    SkAutoTUnref<ExpectationsSource> expectations(SkNEW(NoExpectations));
+    SkAutoTDelete<DM::Expectations> expectations(SkNEW(DM::NoExpectations));
     if (FLAGS_expectations.count() > 0) {
-        expectations.reset(SkNEW_ARGS(JsonExpectationsSource, (FLAGS_expectations[0])));
+        const char* path = FLAGS_expectations[0];
+        if (sk_isdir(path)) {
+            expectations.reset(SkNEW_ARGS(DM::WriteTask::Expectations, (path)));
+        } else {
+            expectations.reset(SkNEW_ARGS(DM::JsonExpectations, (path)));
+        }
     }
 
     DM::Reporter reporter;