Make channel preemption not require view contexts for hookup

ui/gfx/native_widget_types.h

Index: ui/gfx/native_widget_types.h
diff --git a/ui/gfx/native_widget_types.h b/ui/gfx/native_widget_types.h
index 0ce333c5507ddee13243574dd7856e5cc9f944f3..96201452e40c5f9f5dce6253a236230162c51b5c 100644
--- a/ui/gfx/native_widget_types.h
+++ b/ui/gfx/native_widget_types.h
@@ -210,15 +210,13 @@ typedef intptr_t NativeViewId;
   typedef unsigned long PluginWindowHandle;
   const PluginWindowHandle kNullPluginWindow = 0;
 #elif defined(OS_ANDROID)
-  typedef uint64 PluginWindowHandle;
+  typedef uint32 PluginWindowHandle;
   const PluginWindowHandle kNullPluginWindow = 0;
 #elif defined(USE_OZONE)
   typedef intptr_t PluginWindowHandle;
   const PluginWindowHandle kNullPluginWindow = 0;
 #else
-  // On Mac we don't have windowed plugins. We use a NULL/0 PluginWindowHandle
-  // in shared code to indicate there is no window present.
-  typedef bool PluginWindowHandle;
+  typedef uint32 PluginWindowHandle;
   const PluginWindowHandle kNullPluginWindow = 0;
 #endif
 
@@ -230,15 +228,9 @@ enum SurfaceType {
 };
 
 struct GLSurfaceHandle {
-  GLSurfaceHandle()
-      : handle(kNullPluginWindow),
-        transport_type(EMPTY),
-        parent_client_id(0) {
-  }
+  GLSurfaceHandle() : handle(kNullPluginWindow), transport_type(EMPTY) {}
   GLSurfaceHandle(PluginWindowHandle handle_, SurfaceType transport_)
-      : handle(handle_),
-        transport_type(transport_),
-        parent_client_id(0) {
+      : handle(handle_), transport_type(transport_) {
     DCHECK(!is_null() || handle == kNullPluginWindow);
     DCHECK(transport_type != NULL_TRANSPORT ||
            handle == kNullPluginWindow);
@@ -249,7 +241,6 @@ struct GLSurfaceHandle {
   }
   PluginWindowHandle handle;
   SurfaceType transport_type;
-  uint32 parent_client_id;
 };
 
 // AcceleratedWidget provides a surface to compositors to paint pixels.