Plugin Power Saver: Force SW rendering for peripheral plugins.

content/renderer/pepper/ppb_graphics_3d_impl.cc

Index: content/renderer/pepper/ppb_graphics_3d_impl.cc
diff --git a/content/renderer/pepper/ppb_graphics_3d_impl.cc b/content/renderer/pepper/ppb_graphics_3d_impl.cc
index 12d1db923a1440f5bdacea39aa76765ae9934f37..e93f08e0e4c8be0d358042cddb46dcf49f0220c0 100644
--- a/content/renderer/pepper/ppb_graphics_3d_impl.cc
+++ b/content/renderer/pepper/ppb_graphics_3d_impl.cc
@@ -14,6 +14,7 @@
 #include "content/public/common/web_preferences.h"
 #include "content/renderer/pepper/host_globals.h"
 #include "content/renderer/pepper/pepper_plugin_instance_impl.h"
+#include "content/renderer/pepper/pepper_plugin_instance_throttler.h"
 #include "content/renderer/pepper/plugin_module.h"
 #include "content/renderer/render_thread_impl.h"
 #include "content/renderer/render_view_impl.h"
@@ -242,6 +243,11 @@ bool PPB_Graphics3D_Impl::InitRaw(
   if (!prefs.pepper_3d_enabled)
     return false;
 
+  // Force SW rendering for keyframe extraction to avoid pixel reads from VRAM.
+  PepperPluginInstanceThrottler* throttler = plugin_instance->throttler();
+  if (throttler && throttler->needs_representative_keyframe())
+    return false;
+
   RenderThreadImpl* render_thread = RenderThreadImpl::current();
   if (!render_thread)
     return false;