Mojo: use OS whitelists to specify OS-specific typemaps.

Per-OS typemaps are specified by listing them separately, requiring
non-trivial busywork to add an OS-specific typemap, especially for the
first typemap restricted to a particular OS.

Add a new typemap field os_whitelist. If specified in a typemap,
only apply that typemap when targeting an OS included in the whitelist.
For example,

os_whitelist = [ "android", "win" ]

would enable the typemap only if is_android or is_win is true.

Change-Id: I54c32cb131e67b083a4245d171c6d927f6d9df24
Tbr: jam@chromium.org, dcheng@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/784371
Commit-Queue: Sam McNally <sammc@chromium.org>
Reviewed-by: Ken Rockot <rockot@chromium.org>
Cr-Commit-Position: refs/heads/master@{#518859}

content/common/native_types_mac.typemap

@@ -3,6 +3,7 @@
 # found in the LICENSE file.
 
 mojom = "//content/common/native_types.mojom"
+os_whitelist = [ "mac" ]
 public_headers = [
   "//third_party/WebKit/public/platform/WebScrollbarButtonsPlacement.h",
   "//third_party/WebKit/public/platform/mac/WebScrollbarTheme.h",

content/common/typemaps.gni

@@ -6,6 +6,7 @@ typemaps = [
   "//content/common/background_fetch/background_fetch_types.typemap",
   "//content/common/frame_messages.typemap",
   "//content/common/native_types.typemap",
+  "//content/common/native_types_mac.typemap",
   "//content/common/navigation_params.typemap",
   "//content/common/media/media_devices.typemap",
   "//content/common/media/media_stream.typemap",

mojo/public/tools/bindings/chromium_bindings_configuration.gni

@@ -53,10 +53,6 @@ _typemap_imports = [
   "//url/mojo/typemaps.gni",
 ]
 
-_typemap_imports_mac = [ "//content/common/typemaps_mac.gni" ]
-
-_typemap_imports_chromeos = []
-
 _typemaps = []
 foreach(typemap_import, _typemap_imports) {
   # Avoid reassignment error by assigning to empty scope first.
@@ -74,36 +70,4 @@ foreach(typemap, _typemaps) {
       } ]
 }
 
-_typemaps_mac = []
-foreach(typemap_import, _typemap_imports_mac) {
-  _imported = {
-  }
-  _imported = read_file(typemap_import, "scope")
-  _typemaps_mac += _imported.typemaps
-}
-
-typemaps_mac = []
-foreach(typemap, _typemaps_mac) {
-  typemaps_mac += [ {
-        filename = typemap
-        config = read_file(typemap, "scope")
-      } ]
-}
-
-_typemaps_chromeos = []
-foreach(typemap_import, _typemap_imports_chromeos) {
-  _imported = {
-  }
-  _imported = read_file(typemap_import, "scope")
-  _typemaps_chromeos += _imported.typemaps
-}
-
-typemaps_chromeos = []
-foreach(typemap, _typemaps_chromeos) {
-  typemaps_chromeos += [ {
-        filename = typemap
-        config = read_file(typemap, "scope")
-      } ]
-}
-
 component_macro_suffix = ""

mojo/public/tools/bindings/mojom.gni

@@ -113,21 +113,6 @@ if (enable_mojom_typemapping) {
       _typemap_config = typemap.config
       read_file(_typemap_config.mojom, "")
     }
-    if (is_mac && defined(configuration.typemaps_mac)) {
-      foreach(typemap, configuration.typemaps_mac) {
-        _typemap_config = {
-        }
-        _typemap_config = typemap.config
-        read_file(_typemap_config.mojom, "")
-      }
-    } else if (is_chromeos && defined(configuration.typemaps_chromeos)) {
-      foreach(typemap, configuration.typemaps_chromeos) {
-        _typemap_config = {
-        }
-        _typemap_config = typemap.config
-        read_file(_typemap_config.mojom, "")
-      }
-    }
   }
 } else {
   _bindings_configuration_files = []
@@ -622,25 +607,31 @@ template("mojom") {
           }
           _typemap_config = typemap.config
           if (get_path_info(source, "abspath") == _typemap_config.mojom) {
-            active_typemaps += [ typemap ]
-          }
-        }
-        if (is_mac && defined(bindings_configuration.typemaps_mac)) {
-          foreach(typemap, bindings_configuration.typemaps_mac) {
-            _typemap_config = {
-            }
-            _typemap_config = typemap.config
-            if (get_path_info(source, "abspath") == _typemap_config.mojom) {
-              active_typemaps += [ typemap ]
-            }
-          }
-        } else if (is_chromeos &&
-                   defined(bindings_configuration.typemaps_chromeos)) {
-          foreach(typemap, bindings_configuration.typemaps_chromeos) {
-            _typemap_config = {
+            enabled = false
+            if (!defined(_typemap_config.os_whitelist)) {
+              enabled = true
+            } else {
+              foreach(os, _typemap_config.os_whitelist) {
+                if (os == "android" && is_android) {
+                  enabled = true
+                } else if (os == "chromeos" && is_chromeos) {
+                  enabled = true
+                } else if (os == "fuchsia" && is_fuchsia) {
+                  enabled = true
+                } else if (os == "ios" && is_ios) {
+                  enabled = true
+                } else if (os == "linux" && is_linux) {
+                  enabled = true
+                } else if (os == "mac" && is_mac) {
+                  enabled = true
+                } else if (os == "posix" && is_posix) {
+                  enabled = true
+                } else if (os == "win" && is_win) {
+                  enabled = true
+                }
+              }
             }
-            _typemap_config = typemap.config
-            if (get_path_info(source, "abspath") == _typemap_config.mojom) {
+            if (enabled) {
               active_typemaps += [ typemap ]
             }
           }