Bug 785047 - force disable oop when JAWS is running, r=joshmoz

accessible/src/msaa/Makefile.in

@@ -66,6 +66,7 @@ EXPORTS_NAMESPACES = mozilla/a11y \
 
 EXPORTS_mozilla/a11y = \
   AccessibleWrap.h \
+  Compatibility.h \
   HyperTextAccessibleWrap.h \
   $(null)
 

dom/plugins/base/nsNPAPIPlugin.cpp

@@ -94,6 +94,9 @@ using mozilla::plugins::PluginModuleParent;
 #ifdef XP_WIN
 #include <windows.h>
 #include "nsWindowsHelpers.h"
+#ifdef ACCESSIBILITY
+#include "mozilla/a11y/Compatibility.h"
+#endif
 #endif
 
 #ifdef MOZ_WIDGET_ANDROID
@@ -254,11 +257,24 @@ nsNPAPIPlugin::RunPluginOOP(const nsPluginTag *aPluginTag)
     return false;
   }
 
+#ifdef ACCESSIBILITY
+  // Certain assistive technologies don't want oop Flash, thus we have a special
+  // pref for them to disable oop Flash (refer to bug 785047 for details).
+  bool useA11yPref = false;
+#endif
+
 #ifdef XP_WIN
+  useA11yPref =  a11y::Compatibility::IsJAWS();
+
   // On Windows Vista+, we force Flash to run in OOPP mode because Adobe
   // doesn't test Flash in-process and there are known stability bugs.
   if (aPluginTag->mIsFlashPlugin && IsVistaOrLater()) {
+#ifdef ACCESSIBILITY
+    if (!useA11yPref)
       return true;
+#else
+    return true;
+#endif
   }
 #endif
 
@@ -291,6 +307,11 @@ nsNPAPIPlugin::RunPluginOOP(const nsPluginTag *aPluginTag)
   nsAutoCString prefGroupKey("dom.ipc.plugins.enabled.");
 #endif
 
+#ifdef ACCESSIBILITY
+  if (useA11yPref)
+    prefGroupKey.AssignLiteral("dom.ipc.plugins.enabled.a11y.");
+#endif
+
   // Java plugins include a number of different file names,
   // so use the mime type (mIsJavaPlugin) and a special pref.
   if (aPluginTag->mIsJavaPlugin &&
@@ -345,6 +366,9 @@ nsNPAPIPlugin::RunPluginOOP(const nsPluginTag *aPluginTag)
     Preferences::GetBool("dom.ipc.plugins.enabled.ppc", false);
 #endif
 #else
+#ifdef ACCESSIBILITY
+    useA11yPref ? Preferences::GetBool("dom.ipc.plugins.enabled.a11y", false) :
+#endif
     Preferences::GetBool("dom.ipc.plugins.enabled", false);
 #endif
   }