Implement a modal permission dialog on Android gated by a feature.

chrome/browser/permissions/permission_queue_controller.cc

Index: chrome/browser/permissions/permission_queue_controller.cc
diff --git a/chrome/browser/permissions/permission_queue_controller.cc b/chrome/browser/permissions/permission_queue_controller.cc
index 2e272bdbee1349d1a024141d7fa6597d5c03264c..caf2df22a1f2102f32231ece3034a7f4e27de058 100644
--- a/chrome/browser/permissions/permission_queue_controller.cc
+++ b/chrome/browser/permissions/permission_queue_controller.cc
@@ -7,6 +7,7 @@
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/content_settings/host_content_settings_map_factory.h"
 #include "chrome/browser/infobars/infobar_service.h"
+#include "chrome/browser/permissions/permission_dialog_delegate.h"
 #include "chrome/browser/permissions/permission_infobar_delegate.h"
 #include "chrome/browser/permissions/permission_request.h"
 #include "chrome/browser/permissions/permission_request_id.h"
@@ -25,10 +26,15 @@
 
 namespace {
 
-InfoBarService* GetInfoBarService(const PermissionRequestID& id) {
-  content::WebContents* web_contents = tab_util::GetWebContentsByFrameID(
+content::WebContents* GetWebContents(const PermissionRequestID& id) {
+  return tab_util::GetWebContentsByFrameID(
       id.render_process_id(), id.render_frame_id());
-  return web_contents ? InfoBarService::FromWebContents(web_contents) : NULL;
+}
+
+
+InfoBarService* GetInfoBarService(const PermissionRequestID& id) {
+  content::WebContents* web_contents = GetWebContents(id);
+  return web_contents ? InfoBarService::FromWebContents(web_contents) : nullptr;
 }
 
 bool ArePermissionRequestsForSameTab(
@@ -60,6 +66,7 @@ class PermissionQueueController::PendingInfobarRequest {
 
   const PermissionRequestID& id() const { return id_; }
   const GURL& requesting_frame() const { return requesting_frame_; }
+  bool has_gesture() const { return user_gesture_; }
   bool has_infobar() const { return !!infobar_; }
   infobars::InfoBar* infobar() { return infobar_; }
 
@@ -94,7 +101,7 @@ PermissionQueueController::PendingInfobarRequest::PendingInfobarRequest(
       user_gesture_(user_gesture),
       profile_(profile),
       callback_(callback),
-      infobar_(NULL) {}
+      infobar_(nullptr) {}
 
 PermissionQueueController::PendingInfobarRequest::~PendingInfobarRequest() {
 }
@@ -120,9 +127,20 @@ void PermissionQueueController::PendingInfobarRequest::CreateInfoBar(
       &PermissionQueueController::OnPermissionSet, base::Unretained(controller),
       id_, requesting_frame_, embedder_, user_gesture_);
 
-  infobar_ = PermissionInfoBarDelegate::Create(type_, GetInfoBarService(id_),
-                                               requesting_frame_, user_gesture_,
-                                               profile_, callback);
+  if (PermissionDialogDelegate::ShouldShowModalPrompt(user_gesture_)) {

[gone, 2016/10/27 20:33:35]

This is really, really weird as you mentioned.  It'd be less weird if you
renamed the function something like PromptUser or something.

[dominickn, 2016/10/27 23:37:13]

Done.

+    // Only one modal can be shown at a time. This method calls through to Java,
+    // which owns and manages the queue of modal prompts; the bookkeeping in
+    // this class will work as expected:
+    //   i. no pending request will ever have an infobar created for it.
+    //  ii. OnPermissionSet is still called when the user makes a decision.
+    PermissionDialogDelegate::Create(type_, GetWebContents(id_),
+                                     requesting_frame_, user_gesture_, profile_,
+                                     callback);
+  } else {
+    infobar_ = PermissionInfoBarDelegate::Create(
+        type_, GetInfoBarService(id_), requesting_frame_, user_gesture_,
+        profile_, callback);
+  }
 }
 
 PermissionQueueController::PermissionQueueController(
@@ -221,9 +239,10 @@ void PermissionQueueController::OnPermissionSet(const PermissionRequestID& id,
     if (!i->IsForPair(requesting_frame, embedder))
       continue;
     requests_to_notify.push_back(*i);
-    if (!i->has_infobar()) {
-      // We haven't created an infobar yet, just record the pending request
-      // index and remove it later.
+    if (!i->has_infobar() ||
+        PermissionDialogDelegate::ShouldShowModalPrompt(i->has_gesture())) {
+      // We haven't created an infobar yet, or no infobars are being created.
+      // Record the pending request index and remove it later.
       pending_requests_to_remove.push_back(i);
       continue;
     }
@@ -260,8 +279,9 @@ void PermissionQueueController::OnPermissionSet(const PermissionRequestID& id,
 
   // Send out the permission notifications.
   for (PendingInfobarRequests::iterator i = requests_to_notify.begin();
-       i != requests_to_notify.end(); ++i)
+       i != requests_to_notify.end(); ++i) {
     i->RunCallback(content_setting);
+  }
 
   // Remove the pending requests in reverse order.
   for (int i = pending_requests_to_remove.size() - 1; i >= 0; --i)
@@ -328,7 +348,11 @@ void PermissionQueueController::ShowQueuedInfoBarForTab(
   for (PendingInfobarRequests::iterator i = pending_infobar_requests_.begin();
        i != pending_infobar_requests_.end(); ++i) {
     if (ArePermissionRequestsForSameTab(i->id(), id) && !i->has_infobar()) {
-      RegisterForInfoBarNotifications(infobar_service);
+      // When using modal permission prompts, Java controls the display queue,
+      // so infobar notifications are not relevant.
+      if (!PermissionDialogDelegate::ShouldShowModalPrompt(i->has_gesture()))
+        RegisterForInfoBarNotifications(infobar_service);
+
       i->CreateInfoBar(this);
       return;
     }