Make ExtensionInstallPrompt::Prompt ref-counted

chrome/browser/ui/cocoa/extensions/extension_install_view_controller.mm

Index: chrome/browser/ui/cocoa/extensions/extension_install_view_controller.mm
diff --git a/chrome/browser/ui/cocoa/extensions/extension_install_view_controller.mm b/chrome/browser/ui/cocoa/extensions/extension_install_view_controller.mm
index eeb45a33de0f4cb5fc1077dcb838549c09a6fe78..43e361ab9d3ef5c388cdefe3efd9efe04e8bda1c 100644
--- a/chrome/browser/ui/cocoa/extensions/extension_install_view_controller.mm
+++ b/chrome/browser/ui/cocoa/extensions/extension_install_view_controller.mm
@@ -55,7 +55,7 @@ typedef NSUInteger CellAttributes;
                            children:(NSArray*)children;
 - (NSDictionary*)buildDetailToggleItem:(size_t)type
                  permissionsDetailIndex:(size_t)index;
-- (NSArray*)buildWarnings:(const ExtensionInstallPrompt::Prompt&)prompt;
+- (NSArray*)buildWarnings:(scoped_refptr<ExtensionInstallPrompt::Prompt>)prompt;
 - (void)updateViewFrame:(NSRect)frame;
 @end
 
@@ -180,17 +180,17 @@ bool HasAttribute(id item, CellAttributesMask attributeMask) {
 
 - (id)initWithNavigator:(content::PageNavigator*)navigator
                delegate:(ExtensionInstallPrompt::Delegate*)delegate
-                 prompt:(const ExtensionInstallPrompt::Prompt&)prompt {
+                 prompt:(scoped_refptr<ExtensionInstallPrompt::Prompt>)prompt {
   // We use a different XIB in the case of bundle installs, installs with
   // webstore data, or no permission warnings. These are laid out nicely for
   // the data they display.
   NSString* nibName = nil;
-  if (prompt.type() == ExtensionInstallPrompt::BUNDLE_INSTALL_PROMPT) {
+  if (prompt->type() == ExtensionInstallPrompt::BUNDLE_INSTALL_PROMPT) {
     nibName = @"ExtensionInstallPromptBundle";
-  } else if (prompt.has_webstore_data()) {
+  } else if (prompt->has_webstore_data()) {
     nibName = @"ExtensionInstallPromptWebstoreData";
-  } else if (!prompt.ShouldShowPermissions() &&
-             prompt.GetRetainedFileCount() == 0) {
+  } else if (!prompt->ShouldShowPermissions() &&
+             prompt->GetRetainedFileCount() == 0) {
     nibName = @"ExtensionInstallPromptNoWarnings";
   } else {
     nibName = @"ExtensionInstallPrompt";
@@ -200,7 +200,7 @@ bool HasAttribute(id item, CellAttributesMask attributeMask) {
                               bundle:base::mac::FrameworkBundle()])) {
     navigator_ = navigator;
     delegate_ = delegate;
-    prompt_.reset(new ExtensionInstallPrompt::Prompt(prompt));
+    prompt_ = prompt;
     warnings_.reset([[self buildWarnings:prompt] retain]);
   }
   return self;
@@ -547,7 +547,7 @@ bool HasAttribute(id item, CellAttributesMask attributeMask) {
   prompt_->SetIsShowingDetails(
       type, index, !prompt_->GetIsShowingDetails(type, index));
 
-  warnings_.reset([[self buildWarnings:*prompt_] retain]);
+  warnings_.reset([[self buildWarnings:prompt_] retain]);
   [outlineView_ reloadData];
 
   for (id item in warnings_.get())
@@ -589,30 +589,32 @@ bool HasAttribute(id item, CellAttributesMask attributeMask) {
   };
 }
 
-- (NSArray*)buildWarnings:(const ExtensionInstallPrompt::Prompt&)prompt {
+- (NSArray*)buildWarnings:
+                (scoped_refptr<ExtensionInstallPrompt::Prompt>)prompt {

[Scott Hess - ex-Googler, 2014/06/16 19:29:04]

Since you don't actually take a ref of |prompt| in here, a solution which
side-steps my comments below would be to just leave this as a const ref.  Just
because your object is ref-countable doesn't mean that you have to allow
everyone to ref-count it if you know that the original value can't go out of
scope.

[Devlin, 2014/06/17 16:05:26]

Went with this option.  Thanks! :)

   NSMutableArray* warnings = [NSMutableArray array];
   NSString* heading = nil;
 
   ExtensionInstallPrompt::DetailsType type =
       ExtensionInstallPrompt::PERMISSIONS_DETAILS;
-  if (prompt.ShouldShowPermissions()) {
+  if (prompt->ShouldShowPermissions()) {
     NSMutableArray* children = [NSMutableArray array];
-    if (prompt.GetPermissionCount() > 0) {
-      for (size_t i = 0; i < prompt.GetPermissionCount(); ++i) {
-        [children addObject:
-            [self buildItemWithTitle:SysUTF16ToNSString(prompt.GetPermission(i))
-                      cellAttributes:kUseBullet
-                            children:nil]];
+    if (prompt->GetPermissionCount() > 0) {
+      for (size_t i = 0; i < prompt->GetPermissionCount(); ++i) {
+        [children
+            addObject:[self buildItemWithTitle:SysUTF16ToNSString(
+                                                   prompt->GetPermission(i))
+                                cellAttributes:kUseBullet
+                                      children:nil]];

[Scott Hess - ex-Googler, 2014/06/16 19:29:04]

You should feel free to use temporaries to tame the wrapping.  I don't think it
will take any more space, but it will be easier to change going forward. 
Likewise in the three cases below.  This could either be something like:
      NSString* title = SysUTF16ToNSString(prompt->GetPermission(i));
      id child = [self buildItemWithTitle:title
                           cellAttributes:kUseBullet
                                 children:nil];
      [children addObject:child];
or:
      NSString* title = SysUTF16ToNSString(prompt->GetPermission(i));
      [children addObject:[self buildItemWithTitle:title
                                    cellAttributes:kUseBullet
                                          children:nil]];
since each one varies a bit, maybe there's one pattern which is more applicable
than the others.

Of course, it would also work to push the SysUTF16ToNSString() conversion into
-buildItemWithTitle:*, since there are no callers which actually have an
NSString to hand.

 
         // If there are additional details, add them below this item.
-        if (!prompt.GetPermissionsDetails(i).empty()) {
-          if (prompt.GetIsShowingDetails(
-              ExtensionInstallPrompt::PERMISSIONS_DETAILS, i)) {
-            [children addObject:
-                [self buildItemWithTitle:SysUTF16ToNSString(
-                    prompt.GetPermissionsDetails(i))
-                          cellAttributes:kNoExpandMarker
-                                children:nil]];
+        if (!prompt->GetPermissionsDetails(i).empty()) {
+          if (prompt->GetIsShowingDetails(
+                  ExtensionInstallPrompt::PERMISSIONS_DETAILS, i)) {
+            [children addObject:[self buildItemWithTitle:
+                                          SysUTF16ToNSString(
+                                              prompt->GetPermissionsDetails(i))
+                                          cellAttributes:kNoExpandMarker
+                                                children:nil]];
           }
 
           // Add a row for the link.
@@ -621,7 +623,7 @@ bool HasAttribute(id item, CellAttributesMask attributeMask) {
         }
       }
 
-      heading = SysUTF16ToNSString(prompt.GetPermissionsHeading());
+      heading = SysUTF16ToNSString(prompt->GetPermissionsHeading());
     } else {
       [children addObject:
           [self buildItemWithTitle:
@@ -637,26 +639,28 @@ bool HasAttribute(id item, CellAttributesMask attributeMask) {
                   children:children]];
   }
 
-  if (prompt.GetRetainedFileCount() > 0) {
+  if (prompt->GetRetainedFileCount() > 0) {
     type = ExtensionInstallPrompt::RETAINED_FILES_DETAILS;
 
     NSMutableArray* children = [NSMutableArray array];
 
-    if (prompt.GetIsShowingDetails(type, 0)) {
-      for (size_t i = 0; i < prompt.GetRetainedFileCount(); ++i) {
-        [children addObject:
-            [self buildItemWithTitle:SysUTF16ToNSString(
-                prompt.GetRetainedFile(i))
-                      cellAttributes:kUseBullet
-                            children:nil]];
+    if (prompt->GetIsShowingDetails(type, 0)) {
+      for (size_t i = 0; i < prompt->GetRetainedFileCount(); ++i) {
+        [children
+            addObject:[self buildItemWithTitle:SysUTF16ToNSString(
+                                                   prompt->GetRetainedFile(i))
+                                cellAttributes:kUseBullet
+                                      children:nil]];
       }
     }
 
-    [warnings addObject:
-        [self buildItemWithTitle:SysUTF16ToNSString(
-            prompt.GetRetainedFilesHeading())
-                  cellAttributes:kBoldText | kAutoExpandCell | kNoExpandMarker
-                        children:children]];
+    [warnings
+        addObject:[self
+                      buildItemWithTitle:SysUTF16ToNSString(
+                                             prompt->GetRetainedFilesHeading())
+                          cellAttributes:kBoldText | kAutoExpandCell |
+                                         kNoExpandMarker
+                                children:children]];
 
     // Add a row for the link.
     [warnings addObject: