[tracing] Add memory usage of Android UI resources to memory-infra

cc/resources/ui_resource_bitmap.h

Index: cc/resources/ui_resource_bitmap.h
diff --git a/cc/resources/ui_resource_bitmap.h b/cc/resources/ui_resource_bitmap.h
index 23492182b35d359082445f798990b9f607780848..b63db862c984d9b074a74e4b2bbc6f022feee643 100644
--- a/cc/resources/ui_resource_bitmap.h
+++ b/cc/resources/ui_resource_bitmap.h
@@ -51,6 +51,11 @@ class CC_EXPORT UIResourceBitmap {
   UIResourceBitmap(const UIResourceBitmap& other);
   ~UIResourceBitmap();
 
+  // Returns the memory usage of the bitmap.
+  size_t BytesUsed() const {
+    return pixel_ref_ ? pixel_ref_->rowBytes() * size_.height() : 0;

[David Trainor- moved to gerrit, 2016/10/13 04:07:21]

Would pixel_ref_->getAllocatedSizeInBytes() be more correct?  Not sure, just
something to look into.

[ssid, 2016/10/13 17:45:16]

Done.

[ssid, 2016/10/13 18:54:48]

Sorry I misunderstood. Yes, I am planning to make this method public from Skia
side, I will clean up this part when that rolls.

+  }
+
  private:
   friend class AutoLockUIResourceBitmap;