Revert 139366 - [OSX/Pepper] Don't have browser cache shmem ref behind ImageData.

content/renderer/pepper/pepper_platform_image_2d_impl.cc

Index: content/renderer/pepper/pepper_platform_image_2d_impl.cc
===================================================================
--- content/renderer/pepper/pepper_platform_image_2d_impl.cc	(revision 153060)
+++ content/renderer/pepper/pepper_platform_image_2d_impl.cc	(working copy)
@@ -5,8 +5,6 @@
 #include "content/renderer/pepper/pepper_platform_image_2d_impl.h"
 
 #include "build/build_config.h"
-
-#include "base/metrics/histogram.h"
 #include "content/common/view_messages.h"
 #include "content/renderer/render_thread_impl.h"
 #include "ui/surface/transport_dib.h"
@@ -21,14 +19,20 @@
       dib_(dib) {
 }
 
+// On Mac, we have to tell the browser to free the transport DIB.
 PepperPlatformImage2DImpl::~PepperPlatformImage2DImpl() {
+#if defined(OS_MACOSX)
+  if (dib_.get()) {
+    RenderThreadImpl::current()->Send(
+        new ViewHostMsg_FreeTransportDIB(dib_->id()));
+  }
+#endif
 }
 
 // static
 PepperPlatformImage2DImpl* PepperPlatformImage2DImpl::Create(int width,
                                                              int height) {
   uint32 buffer_size = width * height * 4;
-  UMA_HISTOGRAM_COUNTS("Plugin.PepperImage2DSize", buffer_size);
 
   // Allocate the transport DIB and the PlatformCanvas pointing to it.
 #if defined(OS_MACOSX)
@@ -36,10 +40,12 @@
   // 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).
+  // WebPluginDelegateProxy::CreateBitmap() for similar code). The TransportDIB
+  // is cached in the browser, and is freed (in typical cases) by the
+  // PepperPlatformImage2DImpl's destructor.
   TransportDIB::Handle dib_handle;
   IPC::Message* msg = new ViewHostMsg_AllocTransportDIB(buffer_size,
-                                                        false,
+                                                        true,
                                                         &dib_handle);
   if (!RenderThreadImpl::current()->Send(msg))
     return NULL;