Re-land: cc: Use worker context for one-copy tile initialization.

cc/resources/resource_format.cc

Index: cc/resources/resource_format.cc
diff --git a/cc/resources/resource_format.cc b/cc/resources/resource_format.cc
index ce9fe7d93af86d8c511efae63886b1f9df7316aa..122a5cbc512220aaac32d54fa9f10d0c6b5e5986 100644
--- a/cc/resources/resource_format.cc
+++ b/cc/resources/resource_format.cc
@@ -87,4 +87,23 @@ GLenum GLInternalFormat(ResourceFormat format) {
   return GLDataFormat(format);
 }
 
+gfx::GpuMemoryBuffer::Format GpuMemoryBufferFormat(ResourceFormat format) {
+  switch (format) {
+    case RGBA_8888:
+      return gfx::GpuMemoryBuffer::RGBA_8888;
+    case BGRA_8888:
+      return gfx::GpuMemoryBuffer::BGRA_8888;
+    case RGBA_4444:
+      return gfx::GpuMemoryBuffer::RGBA_4444;
+    case ALPHA_8:
+    case LUMINANCE_8:
+    case RGB_565:
+    case ETC1:
+    case RED_8:
+      break;
+  }
+  NOTREACHED();
+  return gfx::GpuMemoryBuffer::RGBA_8888;
+}
+
 }  // namespace cc