TestLauncher: Support multiple filter files

Make --test-launcher-filter-file support multiple filter files separated
by ';'.

Bug: 881438
Change-Id: Ibe17d1e8443cbb490a2d1b8942bb003c96a79525
Reviewed-on: https://chromium-review.googlesource.com/1213866
Commit-Queue: Chong Zhang <chongz@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#590513}

base/test/launcher/test_launcher.cc

@@ -948,11 +948,17 @@ bool TestLauncher::Init() {
   std::vector<std::string> positive_gtest_filter;
 
   if (command_line->HasSwitch(switches::kTestLauncherFilterFile)) {
-    base::FilePath filter_file_path = base::MakeAbsoluteFilePath(
-        command_line->GetSwitchValuePath(switches::kTestLauncherFilterFile));
-    if (!LoadFilterFile(filter_file_path, &positive_file_filter,
-                        &negative_test_filter_))
-      return false;
+    auto filter =
+        command_line->GetSwitchValueNative(switches::kTestLauncherFilterFile);
+    for (auto filter_file :
+         SplitString(filter, FILE_PATH_LITERAL(";"), base::TRIM_WHITESPACE,
+                     base::SPLIT_WANT_ALL)) {
+      base::FilePath filter_file_path =
+          base::MakeAbsoluteFilePath(FilePath(filter_file));
+      if (!LoadFilterFile(filter_file_path, &positive_file_filter,
+                          &negative_test_filter_))
+        return false;
+    }
   }
 
   // Split --gtest_filter at '-', if there is one, to separate into

base/test/launcher/unit_test_launcher.cc

@@ -76,6 +76,7 @@ void PrintUsage() {
           " Other flags:\n"
           "  --test-launcher-filter-file=PATH\n"
           "    Like --gtest_filter, but read the test filter from PATH.\n"
+          "    Supports multiple filter paths separated by ';'.\n"
           "    One pattern per line; lines starting with '-' are exclusions.\n"
           "    See also //testing/buildbot/filters/README.md file.\n"
           "\n"

base/test/test_switches.cc

@@ -23,7 +23,8 @@ const char switches::kTestLauncherDebugLauncher[] =
 const char switches::kTestLauncherForceRunBrokenTests[] =
     "test-launcher-force-run-broken-tests";
 
-// Path to file containing test filter (one pattern per line).
+// List of paths to files (separated by ';') containing test filters (one
+// pattern per line).
 const char switches::kTestLauncherFilterFile[] = "test-launcher-filter-file";
 
 // Whether the test launcher should launch in "interactive mode", which disables

testing/buildbot/filters/README.md

@@ -45,13 +45,22 @@ Example test filter file for excluding a set of tests:
 ## Usage
 
 When running tests on desktop platforms, the test filter file can be specified
-using `--test-launcher-filter-file` command line flag. Example test invocation:
+using `--test-launcher-filter-file` command line flag. Example test invocation
+(single filter file):
 
 ```bash
 $ out/dbg/content_browsertests \
     --test-launcher-filter-file=testing/buildbot/filters/foo.content_browsertests.filter
 ```
 
+Example test invocation (multiple filter files, separated by ';'):
+
+```bash
+$ out/dbg/content_browsertests \
+    --test-launcher-filter-file=testing/buildbot/filters/foo.content_browsertests.filter;\
+                                testing/buildbot/filters/foo.chromeos.content_browsertests.filter
+```
+
 When running tests on Android, the test filter file can also be specified using
 `--test-launcher-filter-file` command line flag. Example test invocation: