Skip gl surface init when headless; enable wm apptests.

Skip native_viewport's init of gfx::GLSurface when headless.
Remove the unused --use-osmesa flag (--use-test-config suffices?).
Re-enable the window_manager_apptests again; fingers crossed.

BUG=480040
TEST=Bot passes window_manager_apptests.
R=sky@chromium.org
TBR=jochen@chromium.org

Review URL: https://codereview.chromium.org/1103413002

Cr-Commit-Position: refs/heads/master@{#327184}

components/native_viewport/main.cc

@@ -37,12 +37,13 @@ class NativeViewportAppDelegate : public mojo::ApplicationDelegate,
     tracing_.Initialize(application);
 
     base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
-    if (command_line->HasSwitch(mojo::kUseTestConfig))
-      gfx::GLSurface::InitializeOneOffForTests();
-    else
-      gfx::GLSurface::InitializeOneOff();
-
     is_headless_ = command_line->HasSwitch(mojo::kUseHeadlessConfig);
+    if (!is_headless_) {
+      if (command_line->HasSwitch(mojo::kUseTestConfig))
+        gfx::GLSurface::InitializeOneOffForTests();
+      else
+        gfx::GLSurface::InitializeOneOff();
+    }
   }
 
   bool ConfigureIncomingConnection(ApplicationConnection* connection) override {

components/native_viewport/public/cpp/args.h

@@ -10,7 +10,6 @@ namespace mojo {
 // All args in alphabetical order. The switches should be documented
 // alongside the definition of their values in the .cc file.
 extern const char kUseHeadlessConfig[];
-extern const char kUseOSMesa[];
 extern const char kUseTestConfig[];
 
 }  // namespace mojo

components/native_viewport/public/cpp/lib/args.cc

@@ -6,12 +6,9 @@
 
 namespace mojo {
 
-// Instead of using the system GL implementation, use OSMesa.
-const char kUseOSMesa[] = "use-osmesa";
-// Loads an app from the specified directory and launches it.
-// Force gl to be initialized in test mode.
-const char kUseTestConfig[] = "use-test-config";
 // Create native viewport in headless mode.
 const char kUseHeadlessConfig[] = "use-headless-config";
+// Force gl to be initialized in test mode.
+const char kUseTestConfig[] = "use-test-config";
 
 }  // namespace mojo

mojo/tools/data/apptests

@@ -44,9 +44,8 @@ tests = [
     "type": "gtest_isolated",
     "shell-args": ["--url-mappings=mojo:window_manager=mojo:test_window_manager"]
   },
-  # TODO(msw): Fix and enable window_manager_apptests: http://crbug.com/480040
-  #{
-  #  "test": "mojo:window_manager_apptests",
-  #  "shell-args": ["--use-test-config", "--use-headless-config"]
-  #},
+  {
+    "test": "mojo:window_manager_apptests",
+    "shell-args": ["--use-headless-config"]
+  },
 ]