Register clipboard image blob in the browser process to copy data less.

content/browser/renderer_host/clipboard_message_filter.cc

Index: content/browser/renderer_host/clipboard_message_filter.cc
diff --git a/content/browser/renderer_host/clipboard_message_filter.cc b/content/browser/renderer_host/clipboard_message_filter.cc
index 7e46a30d7714faba804ad94e7e13cf3fcd561e47..e317c9e81beccc0dcd4131765ce5eef17ab5ce64 100644
--- a/content/browser/renderer_host/clipboard_message_filter.cc
+++ b/content/browser/renderer_host/clipboard_message_filter.cc
@@ -4,7 +4,7 @@
 
 #include "content/browser/renderer_host/clipboard_message_filter.h"
 
-#include <memory>
+#include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ -12,11 +12,16 @@
 #include "base/macros.h"
 #include "base/pickle.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/thread_task_runner_handle.h"
+#include "base/threading/sequenced_worker_pool.h"
 #include "build/build_config.h"
+#include "content/browser/fileapi/chrome_blob_storage_context.h"
 #include "content/common/clipboard_messages.h"
+#include "content/public/browser/blob_handle.h"
 #include "content/public/browser/browser_context.h"
 #include "ipc/ipc_message_macros.h"
 #include "third_party/skia/include/core/SkBitmap.h"
+#include "ui/base/clipboard/clipboard.h"
 #include "ui/base/clipboard/custom_data_helper.h"
 #include "ui/base/clipboard/scoped_clipboard_writer.h"
 #include "ui/gfx/codec/png_codec.h"
@@ -31,13 +36,18 @@ void ReleaseSharedMemoryPixels(void* addr, void* context) {
   delete reinterpret_cast<base::SharedMemory*>(context);
 }
 
+// No-op helper for delayed cleanup of BlobHandles generated by reading
+// clipboard images.
+void CleanupReadImageBlob(std::unique_ptr<content::BlobHandle>) {}
+
 }  // namespace
 
-ClipboardMessageFilter::ClipboardMessageFilter()
+ClipboardMessageFilter::ClipboardMessageFilter(
+    scoped_refptr<ChromeBlobStorageContext> blob_storage_context)
     : BrowserMessageFilter(ClipboardMsgStart),
+      blob_storage_context_(std::move(blob_storage_context)),
       clipboard_writer_(
-          new ui::ScopedClipboardWriter(ui::CLIPBOARD_TYPE_COPY_PASTE)) {
-}
+          new ui::ScopedClipboardWriter(ui::CLIPBOARD_TYPE_COPY_PASTE)) {}
 
 void ClipboardMessageFilter::OverrideThreadForMessage(
     const IPC::Message& message, BrowserThread::ID* thread) {
@@ -54,11 +64,6 @@ void ClipboardMessageFilter::OverrideThreadForMessage(
   if (IPC_MESSAGE_CLASS(message) == ClipboardMsgStart)
     *thread = BrowserThread::UI;
 #endif
-
-#if defined(OS_WIN)
-  if (message.type() == ClipboardHostMsg_ReadImage::ID)
-    *thread = BrowserThread::FILE;
-#endif
 }
 
 bool ClipboardMessageFilter::OnMessageReceived(const IPC::Message& message) {
@@ -175,34 +180,58 @@ void ClipboardMessageFilter::OnReadImage(ui::ClipboardType type,
                                          IPC::Message* reply_msg) {
   SkBitmap bitmap = GetClipboard()->ReadImage(type);
 
-#if defined(USE_X11)
-  BrowserThread::PostTask(
-      BrowserThread::FILE, FROM_HERE,
-      base::Bind(
-          &ClipboardMessageFilter::OnReadImageReply, this, bitmap, reply_msg));
-#else
-  OnReadImageReply(bitmap, reply_msg);
-#endif
+  BrowserThread::GetBlockingPool()
+      ->GetTaskRunnerWithShutdownBehavior(
+          base::SequencedWorkerPool::SKIP_ON_SHUTDOWN)
+      ->PostTask(FROM_HERE,
+                 base::Bind(&ClipboardMessageFilter::ReadAndEncodeImage, this,
+                            bitmap, reply_msg));
 }
 
-void ClipboardMessageFilter::OnReadImageReply(
-    const SkBitmap& bitmap, IPC::Message* reply_msg) {
-  base::SharedMemoryHandle image_handle = base::SharedMemory::NULLHandle();
-  uint32_t image_size = 0;
+void ClipboardMessageFilter::ReadAndEncodeImage(const SkBitmap& bitmap,
+                                                IPC::Message* reply_msg) {
   if (!bitmap.isNull()) {
-    std::vector<unsigned char> png_data;
-    if (gfx::PNGCodec::FastEncodeBGRASkBitmap(bitmap, false, &png_data)) {
-      base::SharedMemory buffer;
-      if (buffer.CreateAndMapAnonymous(png_data.size())) {
-        memcpy(buffer.memory(), png_data.data(), png_data.size());
-        if (buffer.GiveToProcess(PeerHandle(), &image_handle)) {
-          image_size = png_data.size();
-        }
-      }
+    std::unique_ptr<std::vector<uint8_t>> png_data(new std::vector<uint8_t>);
+    if (gfx::PNGCodec::FastEncodeBGRASkBitmap(bitmap, false, png_data.get())) {
+      BrowserThread::PostTask(
+          BrowserThread::IO, FROM_HERE,
+          base::Bind(&ClipboardMessageFilter::OnReadAndEncodeImageFinished,
+                     this, base::Passed(&png_data), reply_msg));
+      return;
+    }
+  }
+  ClipboardHostMsg_ReadImage::WriteReplyParams(reply_msg, std::string(),
+                                               std::string(), -1);
+  Send(reply_msg);
+}
+
+void ClipboardMessageFilter::OnReadAndEncodeImageFinished(
+    std::unique_ptr<std::vector<uint8_t>> png_data,
+    IPC::Message* reply_msg) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (png_data->size() < std::numeric_limits<uint32_t>::max()) {
+    std::unique_ptr<content::BlobHandle> blob_handle =
+        blob_storage_context_->CreateMemoryBackedBlob(
+            reinterpret_cast<char*>(png_data->data()), png_data->size());
+    if (blob_handle) {
+      ClipboardHostMsg_ReadImage::WriteReplyParams(
+          reply_msg, blob_handle->GetUUID(), ui::Clipboard::kMimeTypePNG,
+          static_cast<int64_t>(png_data->size()));
+      Send(reply_msg);
+      // Give the renderer a minute to pick up a reference to the blob before
+      // giving up.
+      // TODO(dmurph): There should be a better way of transferring ownership of
+      // a blob from the browser to the renderer, rather than relying on this
+      // timeout to clean up eventually. See https://crbug.com/604800.
+      base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+          FROM_HERE,
+          base::Bind(&CleanupReadImageBlob, base::Passed(&blob_handle)),
+          base::TimeDelta::FromMinutes(1));
+      return;
     }
   }
-  ClipboardHostMsg_ReadImage::WriteReplyParams(reply_msg, image_handle,
-                                               image_size);
+  ClipboardHostMsg_ReadImage::WriteReplyParams(reply_msg, std::string(),
+                                               std::string(), -1);
   Send(reply_msg);
 }