Add A4A opt-in/out logic

BUILD.gn

@@ -232,22 +232,28 @@ config("angle_feature_support_util_config") {
 }
 
 static_library("angle_feature_support_util") {
-  sources = [
-    "src/feature_support_util/feature_support_util.cpp",
-    "src/feature_support_util/feature_support_util.h",
-  ]
-
   configs -= angle_undefine_configs
   configs += [
     ":internal_config",
     ":extra_warnings",
   ]
 
-  public_configs = [ ":angle_feature_support_util_config" ]
+  public_configs = [
+    ":angle_feature_support_util_config",
+    "third_party/jsoncpp:jsoncpp_config",
+  ]
 
   public_deps = [
     ":angle_common",
   ]
+
+  sources = [
+    "src/feature_support_util/feature_support_util.cpp",
+    "src/feature_support_util/feature_support_util.h",
+  ]
+  deps = [
+    "third_party/jsoncpp:jsoncpp",
+  ]
 }
 
 config("angle_gpu_info_util_config") {
@@ -493,13 +499,15 @@ static_library("libANGLE") {
     ":angle_common",
   ]
   deps = [
-    ":angle_feature_support_util",
     ":angle_gpu_info_util",
     ":angle_image_util",
     ":commit_id",
     ":includes",
     ":translator",
   ]
+  if (is_android) {
+    deps += [ ":angle_feature_support_util" ]
+  }
 
   # Shared D3D sources.
   if (angle_enable_d3d9 || angle_enable_d3d11) {

src/feature_support_util/a4a_rules.json

+R"=====({"Rules":
+ [
+  {"Rule" : "Default Rule (i.e. use native driver)",
+   "AppChoice" : true, "NonChoice" : false
+  },
+  {"Rule" : "Supported application(s) (e.g. Maps on Google devices)",
+   "AppChoice" : true, "NonChoice" : true,
+   "Applications" :
+   [
+    {"AppName" : "com.google.android.apps.maps"}
+   ],
+   "Devices" : 
+   [
+    {"Manufacturer" : "Google"
+    }
+   ]
+  }
+ ]
+}
+)====="

src/feature_support_util/feature_support_util.h

@@ -24,6 +24,16 @@ typedef enum ANGLEPreference {
     ANGLE_PREFER_ANGLE  = 2,
 } ANGLEPreference;
 
+// The Android EGL loader will call this function in order to determine whether
+// to use ANGLE instead of a native OpenGL-ES (GLES) driver.
+//
+// Parameters:
+// - appName - Java name of the application (e.g. "com.google.android.apps.maps")
+// - deviceMfr - Device manufacturer, from the "ro.product.manufacturer"com.google.android" property
+// - deviceModel - Device model, from the "ro.product.model"com.google.android" property
+// - developerOption - Whether the "Developer Options" setting was set, and if so, how
+// - appPreference - Whether the application expressed a preference, and if so, how
+//
 // TODO(ianelliott@google.com angleproject:2801): Revisit this function
 // name/interface.  Look at generalizing it and making it more "feature"
 // oriented.