diff --git a/engine/tonic/dart_library_loader.cc b/engine/tonic/dart_library_loader.cc
index 44f49de3dc3..6e9525eefa5 100644
--- a/engine/tonic/dart_library_loader.cc
+++ b/engine/tonic/dart_library_loader.cc
@@ -21,7 +21,7 @@ using mojo::common::DataPipeDrainer;
 namespace blink {
 
 // A DartLibraryLoader::Job represents a network load. It fetches data from the
-// network and buffers the data in Vector. To cancel the job, delete this
+// network and buffers the data in std::vector. To cancel the job, delete this
 // object.
 class DartLibraryLoader::Job : public DartDependency,
                                public DataPipeDrainer::Client {
@@ -37,7 +37,7 @@ class DartLibraryLoader::Job : public DartDependency,
  protected:
   DartLibraryLoader* loader_;
   // TODO(abarth): Should we be using SharedBuffer to buffer the data?
-  Vector<uint8_t> buffer_;
+  std::vector<uint8_t> buffer_;
 
  private:
   void OnStreamAvailable(mojo::ScopedDataPipeConsumerHandle pipe) {
@@ -50,7 +50,8 @@ class DartLibraryLoader::Job : public DartDependency,
 
   // DataPipeDrainer::Client
   void OnDataAvailable(const void* data, size_t num_bytes) override {
-    buffer_.append(static_cast<const uint8_t*>(data), num_bytes);
+    const uint8_t* bytes = static_cast<const uint8_t*>(data);
+    buffer_.insert(buffer_.end(), bytes, bytes + num_bytes);
   }
   // Subclasses must implement OnDataComplete.
 
@@ -141,20 +142,20 @@ class DartLibraryLoader::WatcherSignaler {
         resolved_dependency_(resolved_dependency) {}
 
   ~WatcherSignaler() {
-    Vector<DependencyWatcher*> completed_watchers;
+    std::vector<DependencyWatcher*> completed_watchers;
     for (const auto& watcher : loader_.dependency_watchers_) {
       if (watcher->DidResolveDependency(resolved_dependency_,
                                         catcher_->dependencies()))
-        completed_watchers.append(watcher.get());
+        completed_watchers.push_back(watcher.get());
     }
 
     // Notice that we remove the dependency catcher and extract all the
     // callbacks before running any of them. We don't want to be re-entered
     // below the callbacks and end up in an inconsistent state.
     catcher_.clear();
-    Vector<base::Closure> callbacks;
+    std::vector<base::Closure> callbacks;
     for (const auto& watcher : completed_watchers) {
-      callbacks.append(watcher->callback());
+      callbacks.push_back(watcher->callback());
       loader_.dependency_watchers_.remove(watcher);
     }
 
@@ -235,8 +236,9 @@ Dart_Handle DartLibraryLoader::CanonicalizeURL(Dart_Handle library,
   return library_provider_->CanonicalizeURL(library, url);
 }
 
-void DartLibraryLoader::DidCompleteImportJob(ImportJob* job,
-                                             const Vector<uint8_t>& buffer) {
+void DartLibraryLoader::DidCompleteImportJob(
+    ImportJob* job,
+    const std::vector<uint8_t>& buffer) {
   DartIsolateScope scope(dart_state_->isolate());
   DartApiScope api_scope;
 
@@ -254,8 +256,9 @@ void DartLibraryLoader::DidCompleteImportJob(ImportJob* job,
   jobs_.remove(job);
 }
 
-void DartLibraryLoader::DidCompleteSourceJob(SourceJob* job,
-                                             const Vector<uint8_t>& buffer) {
+void DartLibraryLoader::DidCompleteSourceJob(
+    SourceJob* job,
+    const std::vector<uint8_t>& buffer) {
   DartIsolateScope scope(dart_state_->isolate());
   DartApiScope api_scope;
 
diff --git a/engine/tonic/dart_library_loader.h b/engine/tonic/dart_library_loader.h
index 566640fb1bb..da962d9cded 100644
--- a/engine/tonic/dart_library_loader.h
+++ b/engine/tonic/dart_library_loader.h
@@ -5,6 +5,7 @@
 #ifndef SKY_ENGINE_TONIC_DART_LIBRARY_LOADER_H_
 #define SKY_ENGINE_TONIC_DART_LIBRARY_LOADER_H_
 
+#include <vector>
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
@@ -12,7 +13,6 @@
 #include "sky/engine/wtf/HashMap.h"
 #include "sky/engine/wtf/HashSet.h"
 #include "sky/engine/wtf/OwnPtr.h"
-#include "sky/engine/wtf/Vector.h"
 #include "sky/engine/wtf/text/WTFString.h"
 
 namespace blink {
@@ -64,8 +64,8 @@ class DartLibraryLoader {
   Dart_Handle Import(Dart_Handle library, Dart_Handle url);
   Dart_Handle Source(Dart_Handle library, Dart_Handle url);
   Dart_Handle CanonicalizeURL(Dart_Handle library, Dart_Handle url);
-  void DidCompleteImportJob(ImportJob* job, const Vector<uint8_t>& buffer);
-  void DidCompleteSourceJob(SourceJob* job, const Vector<uint8_t>& buffer);
+  void DidCompleteImportJob(ImportJob* job, const std::vector<uint8_t>& buffer);
+  void DidCompleteSourceJob(SourceJob* job, const std::vector<uint8_t>& buffer);
   void DidFailJob(Job* job);
 
   DartState* dart_state_;
diff --git a/engine/tonic/dart_snapshot_loader.cc b/engine/tonic/dart_snapshot_loader.cc
index 04b4de01a75..9277da7ff01 100644
--- a/engine/tonic/dart_snapshot_loader.cc
+++ b/engine/tonic/dart_snapshot_loader.cc
@@ -32,7 +32,8 @@ void DartSnapshotLoader::LoadSnapshot(mojo::ScopedDataPipeConsumerHandle pipe,
 }
 
 void DartSnapshotLoader::OnDataAvailable(const void* data, size_t num_bytes) {
-  buffer_.append(static_cast<const uint8_t*>(data), num_bytes);
+  const uint8_t* bytes = static_cast<const uint8_t*>(data);
+  buffer_.insert(buffer_.end(), bytes, bytes + num_bytes);
 }
 
 void DartSnapshotLoader::OnDataComplete() {
diff --git a/engine/tonic/dart_snapshot_loader.h b/engine/tonic/dart_snapshot_loader.h
index 483299a3570..7817665cdae 100644
--- a/engine/tonic/dart_snapshot_loader.h
+++ b/engine/tonic/dart_snapshot_loader.h
@@ -5,13 +5,14 @@
 #ifndef SKY_ENGINE_TONIC_DART_SNAPSHOT_LOADER_H_
 #define SKY_ENGINE_TONIC_DART_SNAPSHOT_LOADER_H_
 
+#include <vector>
+
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "dart/runtime/include/dart_api.h"
 #include "mojo/common/data_pipe_drainer.h"
 #include "sky/engine/wtf/OwnPtr.h"
-#include "sky/engine/wtf/Vector.h"
 #include "sky/engine/wtf/text/WTFString.h"
 
 namespace blink {
@@ -33,7 +34,7 @@ class DartSnapshotLoader : public mojo::common::DataPipeDrainer::Client {
   base::WeakPtr<DartState> dart_state_;
   OwnPtr<mojo::common::DataPipeDrainer> drainer_;
   // TODO(abarth): Should we be using SharedBuffer to buffer the data?
-  Vector<uint8_t> buffer_;
+  std::vector<uint8_t> buffer_;
   base::Closure callback_;
 
   DISALLOW_COPY_AND_ASSIGN(DartSnapshotLoader);