Take advantage of mojo blobs for lifetime management in clipboard code.

Bug: 604800, 769024, 740744
Change-Id: I2267b1015e3c9ad0d3dfe019572ff328557e0112
Reviewed-on: https://chromium-review.googlesource.com/882483Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Reviewed-by: Daniel Murphy <dmurph@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Marijn Kruisselbrink <mek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532042}

content/browser/blob_storage/chrome_blob_storage_context.cc

@@ -25,6 +25,7 @@
 #include "content/public/common/content_features.h"
 #include "services/network/public/cpp/resource_request_body.h"
 #include "storage/browser/blob/blob_data_builder.h"
+#include "storage/browser/blob/blob_impl.h"
 #include "storage/browser/blob/blob_memory_controller.h"
 #include "storage/browser/blob/blob_storage_context.h"
 
@@ -68,6 +69,14 @@ class BlobHandleImpl : public BlobHandle {
 
   std::string GetUUID() override { return handle_->uuid(); }
 
+  blink::mojom::BlobPtr PassBlob() override {
+    blink::mojom::BlobPtr result;
+    storage::BlobImpl::Create(
+        base::MakeUnique<storage::BlobDataHandle>(*handle_),
+        MakeRequest(&result));
+    return result;
+  }
+
  private:
   std::unique_ptr<storage::BlobDataHandle> handle_;
 };

content/browser/renderer_host/clipboard_host_impl.cc

@@ -40,10 +40,6 @@ void ReleaseSharedMemoryPixels(void* addr, void* context) {
   DCHECK_EQ(MOJO_RESULT_OK, result);
 }
 
-// No-op helper for delayed cleanup of BlobHandles generated by reading
-// clipboard images.
-void CleanupReadImageBlob(std::unique_ptr<content::BlobHandle>) {}
-
 }  // namespace
 
 ClipboardHostImpl::ClipboardHostImpl(
@@ -185,12 +181,7 @@ void ClipboardHostImpl::ReadAndEncodeImage(const SkBitmap& bitmap,
     }
   }
   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
-                          base::BindOnce(
-                              [](ReadImageCallback callback) {
-                                std::move(callback).Run(std::string(),
-                                                        std::string(), -1);
-                              },
-                              std::move(callback)));
+                          base::BindOnce(std::move(callback), nullptr));
 }
 
 void ClipboardHostImpl::OnReadAndEncodeImageFinished(
@@ -198,36 +189,21 @@ void ClipboardHostImpl::OnReadAndEncodeImageFinished(
     ReadImageCallback callback) {
   // |blob_storage_context_| must be accessed only on the IO thread.
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  std::string blob_uuid;
-  std::string mime_type;
-  int64_t size = -1;
+  blink::mojom::SerializedBlobPtr blob;
   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) {
-      blob_uuid = blob_handle->GetUUID();
-      mime_type = ui::Clipboard::kMimeTypePNG;
-      size = static_cast<int64_t>(png_data.size());
-      // 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.
-      BrowserThread::PostDelayedTask(
-          BrowserThread::IO, FROM_HERE,
-          base::BindOnce(&CleanupReadImageBlob, base::Passed(&blob_handle)),
-          base::TimeDelta::FromMinutes(1));
+      std::string blob_uuid = blob_handle->GetUUID();
+      blob = blink::mojom::SerializedBlob::New(
+          blob_uuid, ui::Clipboard::kMimeTypePNG,
+          static_cast<int64_t>(png_data.size()),
+          blob_handle->PassBlob().PassInterface());
     }
   }
-  BrowserThread::PostTask(
-      BrowserThread::UI, FROM_HERE,
-      base::BindOnce(
-          [](ReadImageCallback callback, const std::string& blob_uuid,
-             const std::string& mime_type, int64_t size) {
-            std::move(callback).Run(blob_uuid, mime_type, size);
-          },
-          std::move(callback), blob_uuid, mime_type, size));
+  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+                          base::BindOnce(std::move(callback), std::move(blob)));
 }
 
 void ClipboardHostImpl::ReadCustomData(ui::ClipboardType clipboard_type,

content/public/browser/blob_handle.h

@@ -6,6 +6,7 @@
 #define CONTENT_PUBLIC_BROWSER_BLOB_HANDLE_H_
 
 #include <string>
+#include "third_party/WebKit/common/blob/blob.mojom.h"
 
 namespace content {
 
@@ -15,6 +16,7 @@ class BlobHandle {
  public:
   virtual ~BlobHandle() {}
   virtual std::string GetUUID() = 0;
+  virtual blink::mojom::BlobPtr PassBlob() = 0;
 
  protected:
   BlobHandle() {}

third_party/WebKit/Source/core/clipboard/DataObjectItem.cpp

@@ -131,10 +131,8 @@ File* DataObjectItem::GetAsFile() const {
         mojom::ClipboardBuffer::kStandard);
     if (blob_info.size() < 0)
       return nullptr;
-    return File::Create(
-        "image.png", CurrentTimeMS(),
-        BlobDataHandle::Create(blob_info.Uuid(), blob_info.GetType(),
-                               blob_info.size()));
+    return File::Create("image.png", CurrentTimeMS(),
+                        blob_info.GetBlobHandle());
   }
 
   return nullptr;

third_party/WebKit/Source/platform/exported/WebClipboardImpl.cpp

@@ -153,13 +153,12 @@ WebBlobInfo WebClipboardImpl::ReadImage(mojom::ClipboardBuffer buffer) {
   if (!IsValidBufferType(buffer))
     return WebBlobInfo();
 
-  WTF::String blob_uuid;
-  WTF::String type;
-  int64_t size = -1;
-  clipboard_->ReadImage(buffer, &blob_uuid, &type, &size);
-  if (size < 0)
+  mojom::blink::SerializedBlobPtr blob;
+  clipboard_->ReadImage(buffer, &blob);
+  if (!blob)
     return WebBlobInfo();
-  return WebBlobInfo(blob_uuid, type, size);
+  return WebBlobInfo(blob->uuid, blob->content_type, blob->size,
+                     blob->blob.PassHandle());
 }
 
 WebString WebClipboardImpl::ReadCustomData(mojom::ClipboardBuffer buffer,

third_party/WebKit/common/blob/blob.mojom

@@ -45,3 +45,14 @@ interface Blob {
   // identify the blob.
   GetInternalUUID() => (string uuid);
 };
+
+// Struct wrapping a Blob interface pointer.
+// TODO(mek): Once https://crbug.com/696107 is implemented all usage of this
+// struct can be replaced with a simple Blob interface pointer with handle
+// properties for the other attributes.
+struct SerializedBlob {
+  string uuid;
+  string content_type;
+  uint64 size;
+  Blob blob;
+};

third_party/WebKit/common/clipboard/clipboard.mojom

@@ -5,6 +5,7 @@
 module blink.mojom;
 
 import "mojo/common/string16.mojom";
+import "third_party/WebKit/common/blob/blob.mojom";
 import "ui/gfx/geometry/mojo/geometry.mojom";
 import "url/mojo/url.mojom";
 
@@ -51,9 +52,7 @@ interface ClipboardHost {
   ReadRtf(blink.mojom.ClipboardBuffer buffer) => (string result);
 
   [Sync]
-  ReadImage(blink.mojom.ClipboardBuffer buffer) => (string blob_uuid,
-                                                    string mime_type,
-                                                    int64 size);
+  ReadImage(blink.mojom.ClipboardBuffer buffer) => (SerializedBlob? blob);
 
   [Sync]
   ReadCustomData(blink.mojom.ClipboardBuffer buffer,

third_party/WebKit/common/message_port/message_port.mojom

@@ -37,13 +37,3 @@ struct TransferableMessage {
   array<handle<message_pipe>> ports;
 };
 
-// Struct wrapping a Blob interface pointer.
-// TODO(mek): Once https://crbug.com/696107 is implemented all usage of this
-// struct can be replaced with a simple Blob interface pointer with handle
-// properties for the other attributes.
-struct SerializedBlob {
-  string uuid;
-  string content_type;
-  uint64 size;
-  Blob blob;
-};