Disabled build system change polling when auto-resolution is disabled.

Methods that used to be hooked into the editor update tick are now able to be
unhooked and will not automatically be assigned via the PlayServicesResolver's
static constructor if auto resoltution is turned off in the settings.

Original: #173
Change-Id: I91f5019f2dec77f9470f38ac8c9fb978a022d7a6

Author: oddgamesdaniel

source/PlayServicesResolver/src/PlayServicesResolver.cs

@@ -630,6 +630,9 @@ static PlayServicesResolver() {
                     "ProjectSettings",
                     logMessageWithLevel: LogDelegate);
             }
+            RunOnMainThread.OnUpdate -= PollBundleId;
+            RunOnMainThread.OnUpdate += PollBundleId;
+
             // Initialize settings and resolve if required.
             OnSettingsChanged();
 
@@ -642,9 +645,21 @@ static PlayServicesResolver() {
                 ScheduleAutoResolve();
             }
 
-            // Register events to monitor build system changes for the Android Resolver and other
-            // plugins.
-            RunOnMainThread.OnUpdate += PollBundleId;
+            if (GooglePlayServices.SettingsDialog.EnableAutoResolution) LinkAutoResolution();
+        }
+
+       // Unregister events to monitor build system changes for the Android Resolver and other
+       // plugins.
+        public static void UnlinkAutoResolution() {
+            RunOnMainThread.OnUpdate -= PollBuildSystem;
+            RunOnMainThread.OnUpdate -= PollAndroidAbis;
+            RunOnMainThread.OnUpdate -= PollAndroidSdkRoot;
+        }
+
+        // Register events to monitor build system changes for the Android Resolver and other
+        // plugins.
+        public static void LinkAutoResolution() {
+            UnlinkAutoResolution();
             RunOnMainThread.OnUpdate += PollBuildSystem;
             RunOnMainThread.OnUpdate += PollAndroidAbis;
             RunOnMainThread.OnUpdate += PollAndroidSdkRoot;

source/PlayServicesResolver/src/SettingsDialog.cs

@@ -117,7 +117,14 @@ internal static void RestoreDefaultSettings() {
         }
 
         internal static bool EnableAutoResolution {
-            set { projectSettings.SetBool(AutoResolveKey, value); }
+            set {
+                projectSettings.SetBool(AutoResolveKey, value);
+                if (value) {
+                    PlayServicesResolver.LinkAutoResolution();
+                } else {
+                    PlayServicesResolver.UnlinkAutoResolution();
+                }
+            }
             get { return projectSettings.GetBool(AutoResolveKey, true); }
         }