Add acknowledgement messages for PluginMsg_UpdateGeometry. On the Mac, use

these acknowledgements to know when it's safe to dump old TransportDIBs in the
renderer process.  The Mac TransportDIB implementation uses
base::SharedMemory, which cannot be disposed of if an in-flight UpdateGeometry
message refers to the shared memory file descriptor.

BUG=27510, 26754
TEST=1. From bug 25710:
         a. Visit http://www.dkmsoftware.com/Yubotu.htm
         b. Click "Play Now"
         c. Resize vigorously.
        Expect: no sad plug-in icon.
     2. Test case from bug 26754 (affected machines only):
         a. Visit http://news.google.com/
         b. Click the [+] to the left of a YouTube link.  On affected
            machines, you'll get a sad plug-in icon.
         c. Click the [+] to the left of a different YouTube link.
        Expect: no crash.
     3. Test case from bug 26754 comment 9 (affected machines only):
         a. Have lots of bookmarks (import Safari defaults)
         b. Right-click on bookmark bar, and choose "Open All Bookmarks"
        Expect: no crash.
        This change may not actually fix the third test case.
Review URL: http://codereview.chromium.org/417005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@33264 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 21 insertions, 1 deletions

diff --git a/chrome/common/plugin_messages.h b/chrome/common/plugin_messages.h
index c4c70fb..0bfddee 100644
--- a/chrome/common/plugin_messages.h
+++ b/chrome/common/plugin_messages.h
@@ -105,6 +105,14 @@ struct PluginMsg_UpdateGeometry_Param {
   gfx::Rect clip_rect;
   TransportDIB::Handle windowless_buffer;
   TransportDIB::Handle background_buffer;
+
+#if defined(OS_MACOSX)
+  // This field contains a key that the plug-in process is expected to return
+  // to the renderer in its ACK message, unless the value is -1, in which case
+  // no ACK message is required.  Other than the special -1 value, the values
+  // used in ack_key are opaque to the plug-in process.
+  int ack_key;
+#endif
 };
 
 
@@ -418,13 +426,21 @@ struct ParamTraits<PluginMsg_UpdateGeometry_Param> {
     WriteParam(m, p.clip_rect);
     WriteParam(m, p.windowless_buffer);
     WriteParam(m, p.background_buffer);
+#if defined(OS_MACOSX)
+    WriteParam(m, p.ack_key);
+#endif
   }
   static bool Read(const Message* m, void** iter, param_type* r) {
     return
       ReadParam(m, iter, &r->window_rect) &&
       ReadParam(m, iter, &r->clip_rect) &&
       ReadParam(m, iter, &r->windowless_buffer) &&
-      ReadParam(m, iter, &r->background_buffer);
+      ReadParam(m, iter, &r->background_buffer)
+#if defined(OS_MACOSX)
+      &&
+      ReadParam(m, iter, &r->ack_key)
+#endif
+      ;
   }
   static void Log(const param_type& p, std::wstring* l) {
     l->append(L"(");
@@ -435,6 +451,10 @@ struct ParamTraits<PluginMsg_UpdateGeometry_Param> {
     LogParam(p.windowless_buffer, l);
     l->append(L", ");
     LogParam(p.background_buffer, l);
+#if defined(OS_MACOSX)
+    l->append(L", ");
+    LogParam(p.ack_key, l);
+#endif
     l->append(L")");
   }
 };