Add a new metric for how many times permissions prompts are shown.

chrome/browser/ui/website_settings/permission_bubble_request.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_WEBSITE_SETTINGS_PERMISSION_BUBBLE_REQUEST_H_
 #define CHROME_BROWSER_UI_WEBSITE_SETTINGS_PERMISSION_BUBBLE_REQUEST_H_
 
 #include "base/strings/string16.h"
 #include "url/gurl.h"
 
 namespace gfx {
 enum class VectorIconId;
 }
 
+// Used for UMA to record the types of permission prompts shown.
+// This corresponds to the PermissionPromptType enum in
+// src/tools/metrics/histograms.xml. The usual rules of updating UMA values
+// applies to this enum:
+// - don't remove values
+// - only ever add values at the end
+// - keep the PermissionPromptType enum in sync with this definition.

[felt, 2016/04/18 21:15:14]

"Your search - PermissionPromptType - did not match any documents." 
which enum do you mean?

also, in general, I am very wary of requiring future people who update enums to
keep two enums in sync.

[benwells, 2016/04/19 00:09:24]

I don't know of any way to get around needing the two enums. The one in
histograms.xml is just a description of this one for reporting in the UMA front
end.

However I think I should name the enums the same to make it clearer. I had kept
the UMA one more general in case it one day needs to refer to more than just
bubbles (e.g. infobars), but if that ever happens we can just rename it then.

[felt, 2016/04/19 00:21:19]

Ohhhh, I missed that this was the name of the enum in histograms.xml. I thought
you were referring to a histogram somewhere else in C++ code that I couldn't
find. I am not concerned anymore now that I see what was meant.

+enum class PermissionBubbleType {
+  UNKNOWN,
+  MULTIPLE,
+  PERMISSION,
+  QUOTA,
+  DOWNLOAD,
+  MEDIA_STREAM,
+  REGISTER_PROTOCOL_HANDLER,
+  NUM
+};
+
 // Describes the interface a feature utilizing permission bubbles should
 // implement. A class of this type is registered with the permission bubble
 // manager to receive updates about the result of the permissions request
 // from the bubble. It should live until it is unregistered or until
 // RequestFinished is called.
 // Note that no particular guarantees are made about what exact UI surface
 // is presented to the user. The delegate may be coalesced with other bubble
 // requests, or depending on the situation, not shown at all.
 class PermissionBubbleRequest {
  public:
@@ skipping 30 matching lines @@
   // Called when the user has cancelled the permission request. This
   // corresponds to a denial, but is segregated in case the context needs to
   // be able to distinguish between an active refusal or an implicit refusal.
   virtual void Cancelled() = 0;
 
   // The bubble this request was associated with was answered by the user.
   // It is safe for the request to be deleted at this point -- it will receive
   // no further message from the permission bubble system. This method will
   // eventually be called on every request which is not unregistered.
   virtual void RequestFinished() = 0;
+
+  virtual PermissionBubbleType GetPermissionBubbleType() const;
 };
 
 #endif  // CHROME_BROWSER_UI_WEBSITE_SETTINGS_PERMISSION_BUBBLE_REQUEST_H_