Add ProvideModulesToPage() call to DummyPageHolder

Some Blink unit tests are failing after a new Page<Supplement> is
introduced. This CL adds the support of Supplement to DummyPageHolder
by providing modules to it so they can properly have the supplement
for the test.

A test uses PageTestBase class was also patched individually.

This change is required for crrev.com/1456684.

Bug: 837323
Change-Id: I96b1a49e2a7063ac2aa940376be6e264c23cf395
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1572701Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Hongchan Choi <hongchan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652190}

third_party/blink/renderer/core/testing/dummy_page_holder.cc

@@ -33,6 +33,7 @@
 #include <memory>
 
 #include "base/memory/ptr_util.h"
+#include "third_party/blink/renderer/core/core_initializer.h"
 #include "third_party/blink/renderer/core/frame/local_dom_window.h"
 #include "third_party/blink/renderer/core/frame/local_frame.h"
 #include "third_party/blink/renderer/core/frame/local_frame_view.h"
@@ -80,6 +81,8 @@ DummyPageHolder::DummyPageHolder(
   frame_->SetView(LocalFrameView::Create(*frame_, initial_view_size));
   frame_->View()->GetPage()->GetVisualViewport().SetSize(initial_view_size);
   frame_->Init();
+
+  CoreInitializer::GetInstance().ProvideModulesToPage(GetPage(), nullptr);
 }
 
 DummyPageHolder::~DummyPageHolder() {

third_party/blink/renderer/modules/webaudio/audio_context_test.cc

@@ -9,6 +9,7 @@
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/blink/public/platform/web_audio_device.h"
 #include "third_party/blink/public/platform/web_audio_latency_hint.h"
+#include "third_party/blink/renderer/core/core_initializer.h"
 #include "third_party/blink/renderer/core/dom/document.h"
 #include "third_party/blink/renderer/core/testing/page_test_base.h"
 #include "third_party/blink/renderer/platform/scheduler/public/thread.h"
@@ -88,7 +89,10 @@ class AudioContextTest : public PageTestBase {
 
   ~AudioContextTest() override { platform_.reset(); }
 
-  void SetUp() override { PageTestBase::SetUp(IntSize()); }
+  void SetUp() override {
+    PageTestBase::SetUp(IntSize());
+    CoreInitializer::GetInstance().ProvideModulesToPage(GetPage(), nullptr);
+  }
 
   mojom::blink::AudioContextManagerPtr& GetAudioContextManagerPtrFor(
       AudioContext* audio_context) {