[Download Notification] Show preview if downloaded file is image

chrome/utility/chrome_content_utility_client.cc

Index: chrome/utility/chrome_content_utility_client.cc
diff --git a/chrome/utility/chrome_content_utility_client.cc b/chrome/utility/chrome_content_utility_client.cc
index 6b92765c242ba42799f61c81fc3c35829522738e..f8b474bfdcea79012d37c78026a682eaefda1260 100644
--- a/chrome/utility/chrome_content_utility_client.cc
+++ b/chrome/utility/chrome_content_utility_client.cc
@@ -182,6 +182,8 @@ bool ChromeContentUtilityClient::OnMessageReceived(
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(ChromeContentUtilityClient, message)
     IPC_MESSAGE_HANDLER(ChromeUtilityMsg_DecodeImage, OnDecodeImage)
+    IPC_MESSAGE_HANDLER(ChromeUtilityMsg_DecodeImageByHandle,
+                        OnDecodeImageByHandle)
 #if defined(OS_CHROMEOS)
     IPC_MESSAGE_HANDLER(ChromeUtilityMsg_RobustJPEGDecodeImage,
                         OnRobustJPEGDecodeImage)
@@ -294,6 +296,22 @@ void ChromeContentUtilityClient::DecodeImageAndSend(
   ReleaseProcessIfNeeded();
 }
 
+void ChromeContentUtilityClient::OnDecodeImageByHandle(
+    const IPC::PlatformFileForTransit& image_file,
+    bool shrink_to_fit,
+    int request_id) {
+  base::File file = IPC::PlatformFileForTransitToFile(image_file);
+
+  std::vector<unsigned char> image_data(file.GetLength());
+  int read_bytes = file.Read(
+      0, reinterpret_cast<char*>(image_data.data()), file.GetLength());
+  if (read_bytes <= 0) {
+    Send(new ChromeUtilityHostMsg_DecodeImage_Failed(request_id));
+    return;
+  }
+  DecodeImageAndSend(image_data, shrink_to_fit, request_id);
+}
+
 void ChromeContentUtilityClient::OnDecodeImage(
     const std::vector<unsigned char>& encoded_data,
     bool shrink_to_fit,