Add GetDisplayWithDisplayId to display::Screen.

ui/display/screen.h

Index: ui/display/screen.h
diff --git a/ui/display/screen.h b/ui/display/screen.h
index 79a0035d2565e9aa4b27d5723591ecd4397f403b..76899ac759ab549aa19f3d4733cbcbae49d3fad1 100644
--- a/ui/display/screen.h
+++ b/ui/display/screen.h
@@ -55,6 +55,12 @@ class DISPLAY_EXPORT Screen {
   // Returns the list of displays that are currently available.
   virtual std::vector<display::Display> GetAllDisplays() const = 0;
 
+  // Returns true if the display with |display_id| is found and returns that

[sky, 2016/10/06 15:20:03]

Is there a reason this can't be made a helper function and not a pure virtual
function of this class? Doesn't iterating over GetAllDisplays() give you what
you need?

[riajiang, 2016/10/06 18:26:31]

We were thinking to change some subclasses of display::Screen to use ScreenBase
instead to make use of the DisplayList in ScreenBase and to avoid similar code
in those subclasses. DisplayList already has a FindDisplayById(). And
GetAllDisplays() would make a copy. What do you think?

[sky, 2016/10/06 21:28:34]

That seems orthogonal. You could change subclasses to use DisplayList regardless
of this change.
I am more in favor of making GetAllDisplays() return a const vector& and move
this function else where. That makes it easier for subclasses to implement
Screen. WDYT?

+  // display in |display|. Otherwise returns false and |display| remains
+  // untouched.
+  virtual bool GetDisplayWithDisplayId(int64_t display_id,
+                                       display::Display* display) const = 0;
+
   // Returns the display nearest the specified window.
   // If the window is NULL or the window is not rooted to a display this will
   // return the primary display.