[multipaste]One CH entry for files app

Files app copies raw images onto the clipboard by:
1. In JS, save files app metadata.
2. Later, on the chrome side, add raw image data by:
  - Reading step 1's data from Clipboard.
  - Add raw image data.
  - Write to clipboard a second time.

In a way, files app uses the clipboard as a temp variable.

This results in two entries to ClipboardHistory.
Delete the old one, then allow the second Write to create
a new entry in history.

Bug: 1150155
Change-Id: I90649d9b56ebfc538ab962e4c769a869b9d5d082
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2630405Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Alex Newcomer <newcomer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844272}

ash/clipboard/clipboard_history_controller_impl.cc

@@ -373,6 +373,17 @@ bool ClipboardHistoryControllerImpl::DeleteClipboardItemById(
   return false;
 }
 
+bool ClipboardHistoryControllerImpl::DeleteClipboardItemByClipboardData(
+    ui::ClipboardData* data) {
+  for (const auto& item : history()->GetItems()) {
+    if (item.data() == *data) {
+      DeleteClipboardHistoryItem(item);
+      return true;
+    }
+  }
+  return false;
+}
+
 void ClipboardHistoryControllerImpl::OnClipboardHistoryItemAdded(
     const ClipboardHistoryItem& item,
     bool is_duplicate) {

ash/clipboard/clipboard_history_controller_impl.h

@@ -95,6 +95,7 @@ class ASH_EXPORT ClipboardHistoryControllerImpl
   std::vector<std::string> GetHistoryItemIds() const override;
   bool PasteClipboardItemById(const std::string& item_id) override;
   bool DeleteClipboardItemById(const std::string& item_id) override;
+  bool DeleteClipboardItemByClipboardData(ui::ClipboardData* data) override;
 
   // ClipboardHistory::Observer:
   void OnClipboardHistoryItemAdded(const ClipboardHistoryItem& item,

ash/public/cpp/clipboard_history_controller.h

@@ -21,6 +21,10 @@ namespace gfx {
 class Rect;
 }  // namespace gfx
 
+namespace ui {
+class ClipboardData;
+}  // namespace ui
+
 namespace ash {
 class ScopedClipboardHistoryPause;
 
@@ -96,6 +100,9 @@ class ASH_PUBLIC_EXPORT ClipboardHistoryController {
   // Deletes the clipboard item specified by the item id.
   virtual bool DeleteClipboardItemById(const std::string& item_id) = 0;
 
+  // Deletes the clipboard item that matches `data`.
+  virtual bool DeleteClipboardItemByClipboardData(ui::ClipboardData* data) = 0;
+
  protected:
   ClipboardHistoryController();
   virtual ~ClipboardHistoryController();

chrome/browser/ui/ash/clipboard_util.cc

@@ -7,6 +7,7 @@
 #include <stdint.h>
 #include <memory>
 
+#include "ash/public/cpp/clipboard_history_controller.h"
 #include "base/base64.h"
 #include "base/callback.h"
 #include "base/files/file_util.h"
@@ -91,6 +92,12 @@ void CopyImageToClipboard(bool maintain_clipboard,
       std::make_unique<ui::ClipboardData>(
           *ui::ClipboardNonBacked::GetForCurrentThread()->GetClipboardData(
               nullptr));
+
+  // Before modifying the clipboard, remove the old entry in ClipboardHistory.
+  // CopyAndMaintainClipboard will write to the clipboard a second time,
+  // creating a new entry in clipboard history.
+  ash::ClipboardHistoryController::Get()->DeleteClipboardItemByClipboardData(
+      current_data.get());
   CopyAndMaintainClipboard(std::move(current_data), html, png_data,
                            decoded_image);
   std::move(callback).Run(true);