Navigation transitions (web to native app): Revert exit transition (Blink side)

public/web/WebDocument.h

Index: public/web/WebDocument.h
diff --git a/public/web/WebDocument.h b/public/web/WebDocument.h
index 89f55498ddb210ccf59d28fb1252468183ec245e..2bf98b45a98eda7359f0c3d24398e24bd57a6b4a 100644
--- a/public/web/WebDocument.h
+++ b/public/web/WebDocument.h
@@ -121,6 +121,10 @@ public:
     BLINK_EXPORT WebSize maximumScrollOffset() const;
     BLINK_EXPORT void setIsTransitionDocument();
     BLINK_EXPORT void beginExitTransition(const WebString& cssSelector);
+    BLINK_EXPORT void beginExitTransition(const WebString& cssSelector, const bool exitToActivity);

[esprehn, 2014/10/15 18:01:26]

const bool doesn't make any sense, also lets just use an enum and a default
value for the other one.

[Zhen Wang, 2014/10/15 19:50:58]

Why not const bool?

Are we encouraged to use default value in blink? I see somewhere else in chrome
side that people say try not to use default value.

[esprehn, 2014/10/15 20:19:07]

Default values are fine in blink, and const bool and const double don't make any
sense, you're passing by value.

[Zhen Wang, 2014/10/15 23:04:41]

The const here has nothing to do with the caller. It prevents the bool to be
changed inside the function mistakenly. I thought this is a good practice. No?

+    BLINK_EXPORT void revertExitTransition();
+    BLINK_EXPORT void onTransitionElementOpacity(

[esprehn, 2014/10/15 18:01:26]

This seems like a super weird thing to expose. I don't think this should be in
the public API.

[Zhen Wang, 2014/10/15 19:50:58]

The renderer side will call this function to hide/show the transition elements
(not together with beginExitTransition or revertExitTransition). So I think we
need to export it.

[esprehn, 2014/10/15 20:19:07]

It's not an okay API to expose.

[Zhen Wang, 2014/10/15 23:04:41]

What API shall I use so that the renderer can call to hide the transition
element?

+        const WebString& cssSelector, const double opacity);

[esprehn, 2014/10/15 18:01:26]

no const double

[Zhen Wang, 2014/10/15 19:50:58]

Why not?

[esprehn, 2014/10/15 20:19:07]

You're passing by value, it doesn't make sense. What are you telling the caller
about the function by marking it const?

[Zhen Wang, 2014/10/15 23:04:41]

ditto

 
     // Accessibility support. These methods should only be called on the
     // top-level document, because one accessibility cache spans all of