Query the preferred readback config in CopyFromBackingStore

content/browser/frame_host/navigation_entry_screenshot_manager.cc

 // Copyright 2013 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 "content/browser/frame_host/navigation_entry_screenshot_manager.h"
 
 #include "base/command_line.h"
 #include "base/threading/worker_pool.h"
 #include "content/browser/frame_host/navigation_controller_impl.h"
 #include "content/browser/frame_host/navigation_entry_impl.h"
@@ skipping 116 matching lines @@
         owner_->GetEntryAtIndex(i)));
   }
   DCHECK_EQ(GetScreenshotCount(), 0);
 }
 
 void NavigationEntryScreenshotManager::TakeScreenshotImpl(
     RenderViewHost* host,
     NavigationEntryImpl* entry) {
   DCHECK(host && host->GetView());
   DCHECK(entry);
-  host->CopyFromBackingStore(gfx::Rect(),
+  SkBitmap::Config preferred_format = host->PreferredReadbackFormat();
+  host->CopyFromBackingStore(
+      gfx::Rect(),
       host->GetView()->GetViewBounds().size(),
       base::Bind(&NavigationEntryScreenshotManager::OnScreenshotTaken,
                  screenshot_factory_.GetWeakPtr(),
-                 entry->GetUniqueID()));
+                 entry->GetUniqueID()),
+      preferred_format);
 }
 
 void NavigationEntryScreenshotManager::SetMinScreenshotIntervalMS(
     int interval_ms) {
   DCHECK_GE(interval_ms, 0);
   min_screenshot_interval_ms_ = interval_ms;
 }
 
 void NavigationEntryScreenshotManager::OnScreenshotTaken(int unique_id,
                                                      bool success,
@@ skipping 132 matching lines @@
         owner_->GetEntryAtIndex(forward));
     if (ClearScreenshot(entry))
       --screenshot_count;
     ++forward;
   }
   CHECK_GE(screenshot_count, 0);
   CHECK_LE(screenshot_count, kMaxScreenshots);
 }
 
 }  // namespace content