Migrate BrowserAccessibility windows unique id handling to AXPlatformNodeWin.

content/browser/accessibility/browser_accessibility.h

Index: content/browser/accessibility/browser_accessibility.h
diff --git a/content/browser/accessibility/browser_accessibility.h b/content/browser/accessibility/browser_accessibility.h
index e790989dff6231531790fe84b8e7ff798c08ccbd..bfb73f8e4b170bf0f0c3c16a06ee27eafdfc4be6 100644
--- a/content/browser/accessibility/browser_accessibility.h
+++ b/content/browser/accessibility/browser_accessibility.h
@@ -75,7 +75,7 @@ class CONTENT_EXPORT BrowserAccessibility : public ui::AXPlatformNodeDelegate {
 
   virtual ~BrowserAccessibility();
 
-  static BrowserAccessibility* GetFromUniqueID(int32_t unique_id);
+  static BrowserAccessibility* GetFromUniqueId(int32_t unique_id);
 
   // Called only once, immediately after construction. The constructor doesn't
   // take any arguments because in the Windows subclass we use a special
@@ -200,6 +200,8 @@ class CONTENT_EXPORT BrowserAccessibility : public ui::AXPlatformNodeDelegate {
   // Subclasses should override this to support platform reference counting.
   virtual void NativeReleaseReference();
 
+  virtual int32_t unique_id() const;

[dmazzoni, 2017/07/17 08:38:20]

Since this is virtual it needs to get GetUniqueId() now - by convention,
lowercase_with_underscores is only allowed for trivial accessors,
and this definitely isn't!

Is the unique id actually used anywhere other than Windows and
Android? Hopefully it's not...perhaps it'd be clearer to just add some
unique ID code to Android and having no virtual methods rather than
having a unique ID in this file that's actually unused and overridden
on one platform.

+
   //
   // Accessors
   //
@@ -207,7 +209,6 @@ class CONTENT_EXPORT BrowserAccessibility : public ui::AXPlatformNodeDelegate {
   BrowserAccessibilityManager* manager() const { return manager_; }
   bool instance_active() const { return node_ && manager_; }
   ui::AXNode* node() const { return node_; }
-  int32_t unique_id() const { return unique_id_; }
 
   // These access the internal accessibility tree, which doesn't necessarily
   // reflect the accessibility tree that should be exposed on each platform.
@@ -358,10 +359,10 @@ class CONTENT_EXPORT BrowserAccessibility : public ui::AXPlatformNodeDelegate {
   // The underlying node.
   ui::AXNode* node_;
 
+ private:
   // A unique ID, since node IDs are frame-local.
   int32_t unique_id_;
 
- private:
   // |GetInnerText| recursively includes all the text from descendants such as
   // text found in any embedded object. In contrast, |GetText| might include a
   // special character in the place of every embedded object instead of its