[ios] Dispatcher for tab_strip and tab_grid.

ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.mm

Index: ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.mm
diff --git a/ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.mm b/ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.mm
index 3d627cb4bf3c3f30cf2aff46997cf7baf534d6f5..76f4433b60641ff586587312b247809e591bbe14 100644
--- a/ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.mm
+++ b/ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.mm
@@ -5,7 +5,6 @@
 #import "ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.h"
 
 #include "base/mac/foundation_util.h"
-#import "ios/clean/chrome/browser/ui/commands/tab_commands.h"
 #import "ios/clean/chrome/browser/ui/tab_collection/tab_collection_data_source.h"
 #import "ios/clean/chrome/browser/ui/tab_collection/tab_collection_tab_cell.h"
 
@@ -22,7 +21,6 @@
 @implementation TabCollectionViewController
 @synthesize tabs = _tabs;
 @synthesize dataSource = _dataSource;
-@synthesize tabCommandHandler = _tabCommandHandler;
 
 #pragma mark - UIViewController
 
@@ -62,6 +60,18 @@
   return nil;
 }
 
+- (void)showTabAtIndex:(int)index {
+  [NSException

[marq (ping after 24h), 2017/03/30 08:46:18]

We prefer not to raise ObjC exceptions (see
https://google.github.io/styleguide/objcguide.xml?showone=Avoid_Throwing_Exce...).
This is where NOTREACHED() should be used (from base/logging.h):

NOTREACHED() << "You must override " <<
base::SysNSStringToUTF8(NSStringFromSelector(_cmd)) << " in a subclass."

(you will need base/strings/sys_string_conversions.h as well).

[edchin, 2017/03/30 18:15:51]

Done.

+       raise:NSInternalInconsistencyException
+      format:@"You must override %@ in a subclass", NSStringFromSelector(_cmd)];
+}
+
+- (void)closeTabAtIndex:(int)index {
+  [NSException
+       raise:NSInternalInconsistencyException
+      format:@"You must override %@ in a subclass", NSStringFromSelector(_cmd)];
+}
+
 #pragma mark - UICollectionViewDataSource methods
 
 - (NSInteger)numberOfSectionsInCollectionView:
@@ -111,14 +121,14 @@
   NSInteger item = [[self.tabs indexPathForCell:cell] item];
   DCHECK_LE(item, INT_MAX);
   int index = static_cast<int>(item);
-  [self.tabCommandHandler showTabAtIndex:index];
+  [self showTabAtIndex:index];
 }
 
 - (void)deleteButtonPressedForCell:(UICollectionViewCell*)cell {
   NSInteger item = [[self.tabs indexPathForCell:cell] item];
   DCHECK_LE(item, INT_MAX);
   int index = static_cast<int>(item);
-  [self.tabCommandHandler closeTabAtIndex:index];
+  [self closeTabAtIndex:index];
 }
 
 #pragma mark - TabCollectionConsumer methods