Cleanup shared memory handling in DesktopCapturer interface.

webrtc/modules/desktop_capture/win/screen_capturer_win_gdi.cc

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/modules/desktop_capture/win/screen_capturer_win_gdi.h"
 
 #include <assert.h>
 
+#include <utility>
+
 #include "webrtc/modules/desktop_capture/desktop_capture_options.h"
 #include "webrtc/modules/desktop_capture/desktop_frame.h"
 #include "webrtc/modules/desktop_capture/desktop_frame_win.h"
 #include "webrtc/modules/desktop_capture/desktop_region.h"
 #include "webrtc/modules/desktop_capture/differ.h"
 #include "webrtc/modules/desktop_capture/mouse_cursor.h"
 #include "webrtc/modules/desktop_capture/win/cursor.h"
 #include "webrtc/modules/desktop_capture/win/desktop.h"
 #include "webrtc/modules/desktop_capture/win/screen_capture_utils.h"
 #include "webrtc/system_wrappers/include/logging.h"
 #include "webrtc/system_wrappers/include/tick_util.h"
 
 namespace webrtc {
 
 namespace {
 
 // Constants from dwmapi.h.
 const UINT DWM_EC_DISABLECOMPOSITION = 0;
 const UINT DWM_EC_ENABLECOMPOSITION = 1;
 
 const wchar_t kDwmapiLibraryName[] = L"dwmapi.dll";
 
+// SharedMemoryFactory that creates SharedMemory using the deprecated
+// DesktopCapturer::Callback::CreateSharedMemory().
+class CallbackSharedMemoryFactory : public SharedMemoryFactory {
+ public:
+  CallbackSharedMemoryFactory(DesktopCapturer::Callback* callback)
+      : callback_(callback) {}
+  ~CallbackSharedMemoryFactory() override {}
+
+  rtc::scoped_ptr<SharedMemory> CreateSharedMemory(size_t size) override {
+    return rtc_make_scoped_ptr(callback_->CreateSharedMemory(size));
+  }
+
+ private:
+  DesktopCapturer::Callback* callback_;
+};
+
 }  // namespace
 
 ScreenCapturerWinGdi::ScreenCapturerWinGdi(const DesktopCaptureOptions& options)
     : callback_(NULL),
       current_screen_id_(kFullDesktopScreenId),
       desktop_dc_(NULL),
       memory_dc_(NULL),
       dwmapi_library_(NULL),
       composition_func_(NULL),
       set_thread_execution_state_failed_(false) {
@@ skipping 16 matching lines @@
     DeleteDC(memory_dc_);
 
   // Restore Aero.
   if (composition_func_)
     (*composition_func_)(DWM_EC_ENABLECOMPOSITION);
 
   if (dwmapi_library_)
     FreeLibrary(dwmapi_library_);
 }
 
+void ScreenCapturerWinGdi::SetSharedMemoryFactory(
+    rtc::scoped_ptr<SharedMemoryFactory> shared_memory_factory) {
+  shared_memory_factory_ = std::move(shared_memory_factory);
+}
+
 void ScreenCapturerWinGdi::Capture(const DesktopRegion& region) {
   TickTime capture_start_time = TickTime::Now();
 
   queue_.MoveToNextFrame();
 
   // Request that the system not power-down the system, or the display hardware.
   if (!SetThreadExecutionState(ES_DISPLAY_REQUIRED | ES_SYSTEM_REQUIRED)) {
     if (!set_thread_execution_state_failed_) {
       set_thread_execution_state_failed_ = true;
       LOG_F(LS_WARNING) << "Failed to make system & display power assertion: "
@@ skipping 58 matching lines @@
   if (valid)
     current_screen_id_ = id;
   return valid;
 }
 
 void ScreenCapturerWinGdi::Start(Callback* callback) {
   assert(!callback_);
   assert(callback);
 
   callback_ = callback;
+  if (!shared_memory_factory_)
+    shared_memory_factory_.reset(new CallbackSharedMemoryFactory(callback));
 
   // Vote to disable Aero composited desktop effects while capturing. Windows
   // will restore Aero automatically if the process exits. This has no effect
   // under Windows 8 or higher.  See crbug.com/124018.
   if (composition_func_)
     (*composition_func_)(DWM_EC_DISABLECOMPOSITION);
 }
 
 void ScreenCapturerWinGdi::PrepareCaptureResources() {
   // Switch to the desktop receiving user input if different from the current
@@ skipping 69 matching lines @@
 
   DesktopSize size = screen_rect.size();
   // If the current buffer is from an older generation then allocate a new one.
   // Note that we can't reallocate other buffers at this point, since the caller
   // may still be reading from them.
   if (!queue_.current_frame() ||
       !queue_.current_frame()->size().equals(screen_rect.size())) {
     assert(desktop_dc_ != NULL);
     assert(memory_dc_ != NULL);
 
-    size_t buffer_size = size.width() * size.height() *
-        DesktopFrame::kBytesPerPixel;
-    SharedMemory* shared_memory = callback_->CreateSharedMemory(buffer_size);
-
-    rtc::scoped_ptr<DesktopFrame> buffer(
-        DesktopFrameWin::Create(size, shared_memory, desktop_dc_));
+    rtc::scoped_ptr<DesktopFrame> buffer(DesktopFrameWin::Create(
+        size, shared_memory_factory_.get(), desktop_dc_));
     if (!buffer.get())
       return false;
     queue_.ReplaceCurrentFrame(buffer.release());
   }
 
   // Select the target bitmap into the memory dc and copy the rect from desktop
   // to memory.
   DesktopFrameWin* current = static_cast<DesktopFrameWin*>(
       queue_.current_frame()->GetUnderlyingFrame());
   HGDIOBJ previous_object = SelectObject(memory_dc_, current->bitmap());
   if (previous_object != NULL) {
     BitBlt(memory_dc_,
            0, 0, screen_rect.width(), screen_rect.height(),
            desktop_dc_,
            screen_rect.left(), screen_rect.top(),
            SRCCOPY | CAPTUREBLT);
 
     // Select back the previously selected object to that the device contect
     // could be destroyed independently of the bitmap if needed.
     SelectObject(memory_dc_, previous_object);
   }
   return true;
 }
 
 }  // namespace webrtc