[Cronet] Build static libcronet.a for iOS with complete dependencies.

components/cronet/ios/BUILD.gn

Index: components/cronet/ios/BUILD.gn
diff --git a/components/cronet/ios/BUILD.gn b/components/cronet/ios/BUILD.gn
index 716fa0b47ef7212d96362b7236a846d969a6b4b2..e612d070f0eab47412d13ae1161690ee8b9b2ca6 100644
--- a/components/cronet/ios/BUILD.gn
+++ b/components/cronet/ios/BUILD.gn
@@ -32,34 +32,38 @@ process_version("cronet_version_header") {
   ]
 }
 
+_cronet_deps = [
+  ":cronet_version_header",
+  ":generate_accept_languages",
+  "//base:base",
+  "//components/grpc_support",
+  "//components/metrics:metrics",
+  "//components/metrics/proto:proto",
+  "//components/prefs:prefs",
+  "//ios/net:net",
+  "//ios/web:user_agent",
+  "//net",
+  "//url",
+]
+
+_cronet_sources = [
+  "../histogram_manager.cc",
+  "../histogram_manager.h",
+  "../stale_host_resolver.cc",
+  "../stale_host_resolver.h",
+  "../url_request_context_config.cc",
+  "../url_request_context_config.h",
+  "Cronet.h",
+  "Cronet.mm",
+  "cronet_c_for_grpc.h",
+  "cronet_environment.h",
+  "cronet_environment.mm",
+]
+
 source_set("cronet_sources") {
-  deps = [
-    ":cronet_version_header",
-    ":generate_accept_languages",
-    "//base:base",
-    "//components/grpc_support",
-    "//components/metrics:metrics",
-    "//components/metrics/proto:proto",
-    "//components/prefs:prefs",
-    "//ios/net:net",
-    "//ios/web:user_agent",
-    "//net",
-    "//url",
-  ]
+  deps = _cronet_deps
 
-  sources = [
-    "../histogram_manager.cc",
-    "../histogram_manager.h",
-    "../stale_host_resolver.cc",
-    "../stale_host_resolver.h",
-    "../url_request_context_config.cc",
-    "../url_request_context_config.h",
-    "Cronet.h",
-    "Cronet.mm",
-    "cronet_c_for_grpc.h",
-    "cronet_environment.h",
-    "cronet_environment.mm",
-  ]
+  sources = _cronet_sources
 
   include_dirs = [ "//components/grpc_support/include" ]
 
@@ -137,6 +141,71 @@ action("generate_accept_languages") {
   ]
 }
 
+# A static library which contains just _cronet_sources.
+static_library("cronet_static") {
+  deps = _cronet_deps
+
+  sources = _cronet_sources
+
+  visibility = [ ":*" ]
+
+  include_dirs = [ "//components/grpc_support/include" ]
+
+  public_deps = [
+    "//components/grpc_support",
+  ]
+
+  public_headers = [
+    "Cronet.h",
+    "cronet_c_for_grpc.h",
+  ]
+  public_headers += grpc_public_headers
+}
+
+# A static library which contains all dependencies of :cronet_static.
+static_library("cronet_deps_complete") {
+  visibility = [ ":*" ]
+  complete_static_lib = true
+  deps = [
+    ":cronet_static",
+  ]
+}
+
+# A static library which contains cronet and all dependendencies hidden inside.
+action("cronet_hide") {
+  script = "//components/cronet/tools/hide_symbols.py"
+  deps = [
+    ":cronet_deps_complete",
+    ":cronet_static",
+  ]
+  outputs = [
+    "$target_out_dir/$current_cpu/libcronet_hide.a",
+  ]
+  args = [
+    "--input_libs",
+    rebase_path("$target_out_dir/libcronet_static.a", root_build_dir),
+    "--deps_lib",
+    rebase_path("$target_out_dir/libcronet_deps_complete.a", root_build_dir),
+    "--output_obj",
+    rebase_path("$target_out_dir/$current_cpu/libcronet_hide.o",
+                root_build_dir),
+    "--output_lib",
+    rebase_path("$target_out_dir/$current_cpu/libcronet_hide.a",
+                root_build_dir),
+    "--current_cpu",
+    current_cpu,
+  ]
+}
+
+# A fat static library which exports cronet public symbols and hides all dependendencies.
+lipo_binary("libcronet") {
+  arch_binary_target = ":cronet_hide"
+  arch_binary_output = "libcronet_hide.a"
+  output_name = "libcronet.a"
+  enable_stripping = false
+  enable_dsyms = false
+}
+
 if (additional_toolchains == [] || current_toolchain == default_toolchain) {
   _package_dir = "$root_out_dir/cronet"
 
@@ -163,6 +232,7 @@ if (additional_toolchains == [] || current_toolchain == default_toolchain) {
   copy("cronet_package_copy") {
     sources = [
       "$root_out_dir/Cronet.framework",
+      "$target_out_dir/libcronet.a",
       "//AUTHORS",
       "//chrome/VERSION",
     ]
@@ -172,6 +242,7 @@ if (additional_toolchains == [] || current_toolchain == default_toolchain) {
 
     deps = [
       ":cronet_framework",
+      ":libcronet",
     ]
   }