media: Convert mojo media defines to buildflags

media/mojo/BUILD.gn

Index: media/mojo/BUILD.gn
diff --git a/media/mojo/BUILD.gn b/media/mojo/BUILD.gn
index 2a35d7891880084c2f064fa2cf44d206155265b5..d2a7e20d0f8e299ca526c96a01b2b18efee7f637 100644
--- a/media/mojo/BUILD.gn
+++ b/media/mojo/BUILD.gn
@@ -2,8 +2,68 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/buildflag_header.gni")
+import("//media/media_options.gni")
 import("//testing/test.gni")
 
+buildflag_header("features") {
+  header = "features.h"
+
+  enable_mojo_renderer = false
+  enable_mojo_cdm = false
+  enable_mojo_audio_decoder = false
+  enable_mojo_video_decoder = false
+  enable_mojo_media_in_browser_process = false
+  enable_mojo_media_in_gpu_process = false
+  enable_mojo_media_in_utility_process = false
+
+  if (!enable_mojo_media) {
+    assert(mojo_media_services == [], "Mojo media is not enabled")
+    assert(mojo_media_host == "none", "Mojo media is not enabled")
+    assert(!enable_test_mojo_media_client, "Mojo media is not enabled")
+  } else {
+    assert(mojo_media_services != [], "No mojo media service specified")
+    foreach(service, mojo_media_services) {
+      if (service == "renderer") {
+        enable_mojo_renderer = true
+      } else if (service == "cdm") {
+        enable_mojo_cdm = true
+      } else if (service == "audio_decoder") {
+        enable_mojo_audio_decoder = true
+      } else if (service == "video_decoder") {
+        enable_mojo_video_decoder = true
+      } else {
+        assert(false, "Invalid mojo media service: $service")
+      }
+    }
+    assert(
+        enable_mojo_renderer || !enable_runtime_media_renderer_selection,
+        "The mojo renderer must be enabled to use runtime media renderer selection.")
+
+    if (mojo_media_host == "browser") {
+      enable_mojo_media_in_browser_process = true
+    } else if (mojo_media_host == "gpu") {
+      enable_mojo_media_in_gpu_process = true
+    } else if (mojo_media_host == "utility") {
+      enable_mojo_media_in_utility_process = true
+    } else {
+      assert(false, "Invalid mojo media host: $mojo_media_host")
+    }
+  }
+
+  flags = [
+    "ENABLE_MOJO_MEDIA=$enable_mojo_media",
+    "ENABLE_TEST_MOJO_MEDIA_CLIENT=$enable_test_mojo_media_client",
+    "ENABLE_MOJO_RENDERER=$enable_mojo_renderer",
+    "ENABLE_MOJO_CDM=$enable_mojo_cdm",
+    "ENABLE_MOJO_AUDIO_DECODER=$enable_mojo_audio_decoder",
+    "ENABLE_MOJO_VIDEO_DECODER=$enable_mojo_video_decoder",
+    "ENABLE_MOJO_MEDIA_IN_BROWSER_PROCESS=$enable_mojo_media_in_browser_process",
+    "ENABLE_MOJO_MEDIA_IN_GPU_PROCESS=$enable_mojo_media_in_gpu_process",
+    "ENABLE_MOJO_MEDIA_IN_UTILITY_PROCESS=$enable_mojo_media_in_utility_process",
+  ]
+}
+
 source_set("unit_tests") {
   testonly = true
   sources = [