Bump ffi dependencies (flutter#3540)

* Update to FFI 1.0

* Bump CHANGELOG

Author: Tim Sneath

packages/path_provider/path_provider_windows/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.1.0-nullsafety.3
+
+* Bump ffi dependency to 1.0.0
+* Bump win32 dependency to 2.0.0-nullsafety.12
+
 ## 0.1.0-nullsafety.2
 
 * Bump ffi dependency to 0.3.0-nullsafety.1

packages/path_provider/path_provider_windows/lib/src/path_provider_windows_real.dart

@@ -34,7 +34,7 @@ class VersionInfoQuerier {
       if (VerQueryValue(versionInfo, keyPath, valueAddress, length) == 0) {
         return null;
       }
-      return valueAddress.value.unpackString(length.value);
+      return valueAddress.value.toDartString();
     } finally {
       calloc.free(keyPath);
       calloc.free(length);
@@ -64,7 +64,7 @@ class PathProviderWindows extends PathProviderPlatform {
         final error = GetLastError();
         throw WindowsException(error);
       } else {
-        path = buffer.unpackString(length);
+        path = buffer.toDartString();
 
         // GetTempPath adds a trailing backslash, but SHGetKnownFolderPath does
         // not. Strip off trailing backslash for consistency with other methods
@@ -132,7 +132,7 @@ class PathProviderWindows extends PathProviderPlatform {
         }
       }
 
-      final path = pathPtrPtr.value.unpackString(MAX_PATH);
+      final path = pathPtrPtr.value.toDartString();
       return Future.value(path);
     } finally {
       calloc.free(pathPtrPtr);
@@ -183,8 +183,8 @@ class PathProviderWindows extends PathProviderPlatform {
 
       // If there was no product name, use the executable name.
       if (productName == null) {
-        productName = path.basenameWithoutExtension(
-            moduleNameBuffer.unpackString(moduleNameLength));
+        productName =
+            path.basenameWithoutExtension(moduleNameBuffer.toDartString());
       }
 
       return companyName != null

packages/path_provider/path_provider_windows/pubspec.yaml

@@ -1,7 +1,7 @@
 name: path_provider_windows
 description: Windows implementation of the path_provider plugin
 homepage: https://github.com/flutter/plugins/tree/master/packages/path_provider/path_provider_windows
-version: 0.1.0-nullsafety.2
+version: 0.1.0-nullsafety.3
 
 flutter:
   plugin:
@@ -16,8 +16,8 @@ dependencies:
   path: ^1.8.0-nullsafety.3
   flutter:
     sdk: flutter
-  ffi: '>=0.3.0-nullsafety.1 <2.0.0'
-  win32: ^2.0.0-nullsafety.10
+  ffi: ^1.0.0
+  win32: ^2.0.0-nullsafety.12
 
 dev_dependencies:
   flutter_test: