Mac Pepper: Make Image2D's TransportDIB available to the browser.

chrome/renderer/pepper_plugin_delegate_impl.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/pepper_plugin_delegate_impl.h"
 
 #include <cmath>
 
 #include "app/l10n_util.h"
 #include "app/surface/transport_dib.h"
@@ skipping 50 matching lines @@
 
 namespace {
 
 const int32 kDefaultCommandBufferSize = 1024 * 1024;
 
 // Implements the Image2D using a TransportDIB.
 class PlatformImage2DImpl
     : public webkit::ppapi::PluginDelegate::PlatformImage2D {
  public:
   // This constructor will take ownership of the dib pointer.
+  // On Mac, we assume that the dib is cached by the browser, so on destruction
+  // we'll tell the browser to free it.
   PlatformImage2DImpl(int width, int height, TransportDIB* dib)
       : width_(width),
         height_(height),
         dib_(dib) {
   }
 
+#if defined(OS_MACOSX)
+  // On Mac, we have to tell the browser to free the transport DIB.
+  virtual ~PlatformImage2DImpl() {
+    if (dib_.get()) {
+      RenderThread::current()->Send(
+          new ViewHostMsg_FreeTransportDIB(dib_->id()));
+    }
+  }
+#endif
+
   virtual skia::PlatformCanvas* Map() {
     return dib_->GetPlatformCanvas(width_, height_);
   }
 
   virtual intptr_t GetSharedMemoryHandle(uint32* byte_count) const {
     *byte_count = dib_->size();
 #if defined(OS_WIN)
     return reinterpret_cast<intptr_t>(dib_->handle());
 #elif defined(OS_MACOSX)
     return static_cast<intptr_t>(dib_->handle().fd);
@@ skipping 392 matching lines @@
 webkit::ppapi::PluginDelegate::PlatformImage2D*
 PepperPluginDelegateImpl::CreateImage2D(int width, int height) {
   uint32 buffer_size = width * height * 4;
 
   // Allocate the transport DIB and the PlatformCanvas pointing to it.
 #if defined(OS_MACOSX)
   // On the Mac, shared memory has to be created in the browser in order to
   // work in the sandbox.  Do this by sending a message to the browser
   // requesting a TransportDIB (see also
   // chrome/renderer/webplugin_delegate_proxy.cc, method
-  // WebPluginDelegateProxy::CreateBitmap() for similar code).  Note that the
-  // TransportDIB is _not_ cached in the browser; this is because this memory
-  // gets flushed by the renderer into another TransportDIB that represents the
-  // page, which is then in turn flushed to the screen by the browser process.
-  // When |transport_dib_| goes out of scope in the dtor, all of its shared
-  // memory gets reclaimed.
+  // WebPluginDelegateProxy::CreateBitmap() for similar code). The TransportDIB
+  // is cached in the browser, and is freed (in typical cases) by the
+  // PlatformImage2DImpl's destructor.
   TransportDIB::Handle dib_handle;
   IPC::Message* msg = new ViewHostMsg_AllocTransportDIB(buffer_size,
-                                                        false,
+                                                        true,
                                                         &dib_handle);
   if (!RenderThread::current()->Send(msg))
     return NULL;
   if (!TransportDIB::is_valid(dib_handle))
     return NULL;
 
   TransportDIB* dib = TransportDIB::Map(dib_handle);
 #else
   static int next_dib_id = 0;
   TransportDIB* dib = TransportDIB::Create(buffer_size, next_dib_id++);
@@ skipping 366 matching lines @@
 }
 
 void PepperPluginDelegateImpl::DidStopLoading() {
   render_view_->DidStopLoadingForPlugin();
 }
 
 void PepperPluginDelegateImpl::SetContentRestriction(int restrictions) {
   render_view_->Send(new ViewHostMsg_UpdateContentRestrictions(
       render_view_->routing_id(), restrictions));
 }