Implement fallback from WMPI to WMPA.

content/browser/gpu/gpu_data_manager_impl_private.cc

Index: content/browser/gpu/gpu_data_manager_impl_private.cc
diff --git a/content/browser/gpu/gpu_data_manager_impl_private.cc b/content/browser/gpu/gpu_data_manager_impl_private.cc
index 926886d3e8baa457f780b054064c5bb8e481d2a6..bb8e0337f57c2a20f0e9ca5e00961204f1f58e62 100644
--- a/content/browser/gpu/gpu_data_manager_impl_private.cc
+++ b/content/browser/gpu/gpu_data_manager_impl_private.cc
@@ -933,6 +933,22 @@ bool GpuDataManagerImplPrivate::ShouldDisableAcceleratedVideoDecode(
     return true;
   if (group_name == "Disabled")
     return true;
+
+  // Accelerated decode is never available with --disable-gpu. It is also
+  // currently non-functional with --single-process and --in-process-gpu, but
+  // these should be fixable. We set the --disable-accelerated-video-decode flag
+  // in these cases so that the renderer can be aware. (Which is important on
+  // Android where there is no fallback once WMPI is selected.)
+  //
+  // TODO(sandersd): Enable support for accelerated decode with
+  // --in-process-gpu, at least on Android (necessary to support WebView).
+  // http://crbug.com/574935.
+  if (command_line->HasSwitch(switches::kDisableGpu) ||
+      command_line->HasSwitch(switches::kSingleProcess) ||
+      command_line->HasSwitch(switches::kInProcessGPU)) {
+    return true;
+  }
+
   return false;
 }