Allow creating SharedBitmaps backed by new[]

cc/resources/shared_bitmap.cc

Index: cc/resources/shared_bitmap.cc
diff --git a/cc/resources/shared_bitmap.cc b/cc/resources/shared_bitmap.cc
index 6d2ff0af5d5e41049e852f8bd1f7725f5a5b055f..31cf245151c7cdab6a3a77092b11863d3a666d60 100644
--- a/cc/resources/shared_bitmap.cc
+++ b/cc/resources/shared_bitmap.cc
@@ -14,7 +14,18 @@ SharedBitmap::SharedBitmap(
     base::SharedMemory* memory,
     const SharedBitmapId& id,
     const base::Callback<void(SharedBitmap* bitmap)>& free_callback)
-    : memory_(memory), id_(id), free_callback_(free_callback) {}
+    : memory_(memory),
+      pixels_(static_cast<uint8*>(memory_->memory())),
+      id_(id),
+      free_callback_(free_callback) {
+}
+
+SharedBitmap::SharedBitmap(
+    uint8* pixels,
+    const SharedBitmapId& id,
+    const base::Callback<void(SharedBitmap* bitmap)>& free_callback)
+    : memory_(NULL), pixels_(pixels), id_(id), free_callback_(free_callback) {
+}
 
 SharedBitmap::~SharedBitmap() { free_callback_.Run(this); }