Add some plumbing for the color management of canvases

third_party/WebKit/public/platform/WebExternalTextureMailbox.h

Index: third_party/WebKit/public/platform/WebExternalTextureMailbox.h
diff --git a/third_party/WebKit/public/platform/WebExternalTextureMailbox.h b/third_party/WebKit/public/platform/WebExternalTextureMailbox.h
index 0bb41cfd87bcb188c2c6d0c8caafad4a93ae54dc..e75eafa26d11eb854c88beeca17a83311a2cdb6e 100644
--- a/third_party/WebKit/public/platform/WebExternalTextureMailbox.h
+++ b/third_party/WebKit/public/platform/WebExternalTextureMailbox.h
@@ -33,6 +33,8 @@
 
 #include "WebSize.h"
 
+class SkColorSpace;
+
 namespace blink {
 
 struct WebExternalTextureMailbox {
@@ -43,12 +45,15 @@ struct WebExternalTextureMailbox {
     bool nearestNeighbor = false;
     unsigned textureTarget = 0;
     WebSize textureSize;
+    const SkColorSpace* colorSpace;
 
     WebExternalTextureMailbox()
     {
         memset(name, 0, sizeof(name));
         memset(syncToken, 0, sizeof(syncToken));
     }
+
+    ~WebExternalTextureMailbox() { }
 };
 
 inline bool nameEquals(const WebExternalTextureMailbox& a, const WebExternalTextureMailbox& b)