cc: Remove the software compositing bool from PrepareTextureMailbox

cc/output/renderer_capabilities.cc

Index: cc/output/renderer_capabilities.cc
diff --git a/cc/output/renderer_capabilities.cc b/cc/output/renderer_capabilities.cc
index 1ad2424a5376c3d0d445b142fa8209ad887666c4..9a8ec3a354ff34fa8ff3ee585d8fceaf1bf7ad43 100644
--- a/cc/output/renderer_capabilities.cc
+++ b/cc/output/renderer_capabilities.cc
@@ -7,12 +7,9 @@
 namespace cc {
 
 RendererCapabilities::RendererCapabilities(ResourceFormat best_texture_format,
-                                           int max_texture_size,
-                                           bool using_shared_memory_resources)
+                                           int max_texture_size)
     : best_texture_format(best_texture_format),
-      max_texture_size(max_texture_size),
-      using_shared_memory_resources(using_shared_memory_resources) {
-}
+      max_texture_size(max_texture_size) {}
 
 RendererCapabilities::RendererCapabilities() = default;
 RendererCapabilities::~RendererCapabilities() = default;