Create only a single LegacyRenderWidgetHostHWND per WebContentsViewAura.

ui/views/controls/webview/webview_interactive_uitest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/controls/webview/webview.h"
 
 #include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/test/test_browser_context.h"
 #include "content/public/test/test_browser_thread.h"
 #include "ui/base/ime/text_input_focus_manager.h"
 #include "ui/base/ui_base_switches.h"
 #include "ui/gl/gl_surface.h"
 #include "ui/views/test/webview_test_helper.h"
 #include "ui/views/test/widget_test.h"
 
+#if defined(OS_WIN)
+#include "ui/gfx/win/dpi.h"
+#endif
+
 namespace {
 
 class WebViewInteractiveUiTest : public views::test::WidgetTest {
  public:
   WebViewInteractiveUiTest()
       : ui_thread_(content::BrowserThread::UI, base::MessageLoop::current()) {}
 
   void SetUp() override {
     gfx::GLSurface::InitializeOneOffForTests();
     WidgetTest::SetUp();
+#if defined(OS_WIN)
+    gfx::InitDeviceScaleFactor(1.0f);
+#endif
   }
 
  protected:
   content::BrowserContext* browser_context() { return &browser_context_; }
 
  private:
   content::TestBrowserContext browser_context_;
   views::WebViewTestHelper webview_test_helper_;
   content::TestBrowserThread ui_thread_;
 
@@ skipping 35 matching lines @@
   ui::TextInputClient* client2 = webview->GetTextInputClient();
   EXPECT_NE(null_text_input_client, client2);
   EXPECT_EQ(text_input_focus_manager->GetFocusedTextInputClient(), client2);
   EXPECT_NE(client1, client2);
 
   widget->Close();
   RunPendingMessages();
 }
 
 }  // namespace