add --dryRun flag to dm

dm/DM.cpp

 // Main binary for DM.
 // For a high-level overview, please see dm/README.
 
 #include "SkBenchmark.h"
 #include "SkCommandLineFlags.h"
 #include "SkForceLinking.h"
 #include "SkGraphics.h"
 #include "SkPicture.h"
 #include "SkString.h"
 #include "Test.h"
@@ skipping 33 matching lines @@
 DEFINE_string(match, "",  "[~][^]substring[$] [...] of GM name to run.\n"
                           "Multiple matches may be separated by spaces.\n"
                           "~ causes a matching GM to always be skipped\n"
                           "^ requires the start of the GM to match\n"
                           "$ requires the end of the GM to match\n"
                           "^ and $ requires an exact match\n"
                           "If a GM does not match any list entry,\n"
                           "it is skipped unless some list entry starts with ~");
 DEFINE_string(config, "565 8888 gpu nonrendering",
               "Options: 565 8888 gpu nonrendering msaa4 msaa16 nvprmsaa4 nvprmsaa16 gpunull gpudebug angle mesa");
+DEFINE_bool(dryRun, false, "Just print the tests that would be run, without actually running them.");
 DEFINE_bool(leaks, false, "Print leaked instance-counted objects at exit?");
 DEFINE_string(skps, "", "Directory to read skps from.");
 
 DEFINE_bool(gms, true, "Run GMs?");
 DEFINE_bool(benches, true, "Run benches?  Does not run GMs-as-benches.");
 DEFINE_bool(tests, true, "Run tests?");
 
+DECLARE_bool(verbose);
+
 __SK_FORCE_IMAGE_DECODER_LINKING;
 
 // "FooBar" -> "foobar".  Obviously, ASCII only.
 static SkString lowercase(SkString s) {
     for (size_t i = 0; i < s.size(); i++) {
         s[i] = tolower(s[i]);
     }
     return s;
 }
 
@@ skipping 130 matching lines @@
         if (!SkCommandLineFlags::ShouldSkip(FLAGS_match, forName->getName())) {
             *out->append() = reg->factory();
         }
     }
 }
 
 int tool_main(int argc, char** argv);
 int tool_main(int argc, char** argv) {
     SkAutoGraphics ag;
     SkCommandLineFlags::Parse(argc, argv);
+
+    if (FLAGS_dryRun) {
+        FLAGS_verbose = true;
+    }
 #if SK_ENABLE_INST_COUNT
     gPrintInstCount = FLAGS_leaks;
 #endif
     GM::SetResourcePath(FLAGS_resources[0]);
     SkBenchmark::SetResourcePath(FLAGS_resources[0]);
     Test::SetResourcePath(FLAGS_resources[0]);
 
     SkTArray<SkString> configs;
     for (int i = 0; i < FLAGS_config.count(); i++) {
         SkStrSplit(FLAGS_config[i], ", ", &configs);
@@ skipping 42 matching lines @@
     reporter.getFailures(&failures);
     report_failures(failures);
     return failures.count() > 0;
 }
 
 #if !defined(SK_BUILD_FOR_IOS) && !defined(SK_BUILD_FOR_NACL)
 int main(int argc, char** argv) {
     return tool_main(argc, argv);
 }
 #endif