GetScaleFactorForNativeView should return scale factor in float

chrome/browser/thumbnails/thumbnail_tab_helper.cc

 // Copyright (c) 2012 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 "chrome/browser/thumbnails/thumbnail_tab_helper.h"
 
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/thumbnails/thumbnail_service.h"
 #include "chrome/browser/thumbnails/thumbnail_service_factory.h"
@@ skipping 78 matching lines @@
   gfx::Rect copy_rect = gfx::Rect(view->GetViewBounds().size());
   // Clip the pixels that will commonly hold a scrollbar, which looks bad in
   // thumbnails.
   int scrollbar_size = gfx::scrollbar_size();
   gfx::Size copy_size;
   copy_rect.Inset(0, 0, scrollbar_size, scrollbar_size);
 
   if (copy_rect.IsEmpty())
     return;
 
+  ui::ScaleFactor scale_factor =
+      ui::GetSupportedScaleFactor(
+          ui::GetScaleFactorForNativeView(view->GetNativeView()));
   context->clip_result = algorithm->GetCanvasCopyInfo(
       copy_rect.size(),
-      ui::GetScaleFactorForNativeView(view->GetNativeView()),
+      scale_factor,
       &copy_rect,
       &context->requested_copy_size);
   render_widget_host->CopyFromBackingStore(
       copy_rect,
       context->requested_copy_size,
       base::Bind(&ProcessCapturedBitmap, context, algorithm),
       SkBitmap::kARGB_8888_Config);
 }
 
 }  // namespace
@@ skipping 104 matching lines @@
         content::NOTIFICATION_RENDER_WIDGET_VISIBILITY_CHANGED,
         content::Source<RenderWidgetHost>(renderer));
   }
 }
 
 void ThumbnailTabHelper::WidgetHidden(RenderWidgetHost* widget) {
   if (!enabled_)
     return;
   UpdateThumbnailIfNecessary(web_contents());
 }