[ios] Convert GN libs lists to frameworks in //ios/public.

GN recently added support for Apple frameworks to link, rather than
overloading the libs lists. This pulls .frameworks out of the libs
lists, so that GN can stop supporting .frameworks in libs in the
future.

Bug: 1052560
Change-Id: I494e828033221636b70c618e46bca99ec9e5aa98
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2276415
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Rohit Rao <rohitrao@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#784398}

ios/public/provider/chrome/browser/BUILD.gn

@@ -23,7 +23,7 @@ source_set("browser") {
     "//ios/web/public",
     "//url",
   ]
-  libs = [ "CoreLocation.framework" ]
+  frameworks = [ "CoreLocation.framework" ]
 }
 
 source_set("test_support") {

ios/public/provider/chrome/browser/images/BUILD.gn

@@ -13,7 +13,7 @@ source_set("images") {
     "//base",
     "//components/search_engines",
   ]
-  libs = [ "UIKit.framework" ]
+  frameworks = [ "UIKit.framework" ]
 }
 
 source_set("test_support") {

ios/public/provider/chrome/browser/spotlight/BUILD.gn

@@ -9,7 +9,7 @@ source_set("spotlight") {
     "spotlight_provider.mm",
   ]
   deps = [ "//base" ]
-  libs = [ "Foundation.framework" ]
+  frameworks = [ "Foundation.framework" ]
 }
 
 source_set("test_support") {

ios/public/provider/chrome/browser/ui/BUILD.gn

@@ -13,5 +13,5 @@ source_set("ui") {
     "//base",
     "//ios/public/provider/chrome/browser/voice",
   ]
-  libs = [ "CoreGraphics.framework" ]
+  frameworks = [ "CoreGraphics.framework" ]
 }