Infrastructure for temportarily relinquishing GPU resources.

content/common/gpu/gpu_messages.h

Index: content/common/gpu/gpu_messages.h
diff --git a/content/common/gpu/gpu_messages.h b/content/common/gpu/gpu_messages.h
index 839de2d55a966c6ffa14103d08ecc30aee75f7b0..ede746d43e89c072a31e361bc2aeb6ca643d26a9 100644
--- a/content/common/gpu/gpu_messages.h
+++ b/content/common/gpu/gpu_messages.h
@@ -301,6 +301,11 @@ IPC_MESSAGE_CONTROL0(GpuMsg_DisableWatchdog)
 // Tells the GPU process that the browser has seen a GPU switch.
 IPC_MESSAGE_CONTROL0(GpuMsg_GpuSwitched)
 
+// Tells the GPU process to relinquish the display to an external process.
+// Creating a new surface will automatically re-acquire the display.
+IPC_MESSAGE_CONTROL0(GpuMsg_RelinquishDisplay)
+IPC_MESSAGE_CONTROL0(GpuMsg_DeleteDefaultOffscreenSurface)
+
 //------------------------------------------------------------------------------
 // GPU Host Messages
 // These are messages to the browser.
@@ -402,6 +407,10 @@ IPC_MESSAGE_CONTROL1(GpuHostMsg_DidDestroyOffscreenContext,
 IPC_MESSAGE_CONTROL1(GpuHostMsg_GpuMemoryUmaStats,
                      content::GPUMemoryUmaStats /* GPU memory UMA stats */)
 
+// Response to GpuMsg_RelinquishDisplay
+IPC_MESSAGE_CONTROL1(GpuHostMsg_ResourceRelinquished,
+                     bool /* success */)
+
 //------------------------------------------------------------------------------
 // GPU Channel Messages
 // These are messages from a renderer process to the GPU process.