Remove android_64bit_browser flag

This flag was added as a means of swapping the ABIs of a 64-bit build,
to get a 64-bit browser instead of 32.  There are now build targets to
achieve the same thing, so the flag can be removed.

On a 64-bit configuration, you can now build:

- monochrome_public_bundle: 32-bit browser w/ 64-bit WebView
- monochrome_64_32_public_bundle: 64-bit browser w/ 32-bit WebView
- monochrome_64_public_bundle: 64-bit browser

BUG=907640

Change-Id: Id021645ac9b411510fdf23c09428d3d888a857f5
Reviewed-on: https://chromium-review.googlesource.com/c/1458360Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Richard Coles <torne@chromium.org>
Commit-Queue: Christopher Grant <cjgrant@chromium.org>
Cr-Commit-Position: refs/heads/master@{#630000}

android_webview/system_webview_apk_tmpl.gni

@@ -7,7 +7,6 @@ import("//build/config/android/chrome_version.gni")
 import("//build/config/android/config.gni")
 import("//build/config/android/rules.gni")
 import("//build/config/locales.gni")
-import("//chrome/android/chrome_public_apk_tmpl.gni")
 
 template("system_webview_apk_tmpl") {
   android_apk(target_name) {
@@ -42,19 +41,10 @@ template("system_webview_apk_tmpl") {
       # Include placeholder libraries to ensure we are treated as the desired
       # architecture.
       if (android_64bit_target_cpu) {
-        if (android_64bit_browser) {
-          native_lib_placeholders = [ "libdummy.so" ]
-          if (build_apk_secondary_abi) {
-            secondary_abi_shared_libraries = [
-              "//android_webview:monochrome($android_secondary_abi_toolchain)",
-            ]
-          }
-        } else {
         shared_libraries = [ "//android_webview:monochrome" ]
         if (build_apk_secondary_abi) {
           secondary_native_lib_placeholders = [ "libdummy.so" ]
         }
-        }
       } else {
         native_lib_placeholders = [ "libdummy.so" ]
       }

chrome/android/BUILD.gn

@@ -1085,7 +1085,7 @@ if (current_toolchain == default_toolchain) {
         if (_is_monochrome) {
           # Always use the 32-bit library's whitelist since the 64-bit one is
           # webview-only.
-          if (!android_64bit_target_cpu || android_64bit_browser) {
+          if (!android_64bit_target_cpu) {
             _fat_lib_toolchain = current_toolchain
           } else {
             _fat_lib_toolchain = android_secondary_abi_toolchain
@@ -1269,7 +1269,8 @@ template("libmonochrome_apk_or_bundle_tmpl") {
   }
 }
 
-if (!android_64bit_target_cpu || !current_abi_is_webview_only) {
+if (!android_64bit_target_cpu ||
+    current_toolchain == android_secondary_abi_toolchain) {
   # Monochrome APK native library.
   libmonochrome_apk_or_bundle_tmpl("monochrome") {
   }

chrome/android/chrome_public_apk_tmpl.gni

@@ -24,9 +24,6 @@ declare_args() {
 
   # Enable language splits in the Chrome bundles.
   enable_chrome_language_splits = android_channel == "default"
-
-  # Build Monochrome/Trichrome as a 64-bit browser.
-  android_64bit_browser = false
 }
 
 default_chrome_public_jinja_variables = [
@@ -35,16 +32,6 @@ default_chrome_public_jinja_variables = [
   "include_arcore_manifest_flag=$package_arcore",
 ]
 
-if (android_64bit_browser) {
-  current_abi_is_webview_only =
-      defined(android_secondary_abi_toolchain) &&
-      current_toolchain == android_secondary_abi_toolchain
-} else {
-  current_abi_is_webview_only =
-      defined(android_secondary_abi_toolchain) &&
-      current_toolchain != android_secondary_abi_toolchain
-}
-
 # A template used to declare any target that will implement a full Chromium
 # or Chrome application, either as an APK, or an app bundle module.
 #
@@ -284,11 +271,9 @@ template("monochrome_public_common_apk_or_module_tmpl") {
       if (android_64bit_target_cpu) {
         # Build //android_webview:monochrome with the opposite bitness that
         # Chrome runs in.
-        if ((defined(invoker.is_64_bit_browser) && invoker.is_64_bit_browser) ||
-            android_64bit_browser) {
+        if (defined(invoker.is_64_bit_browser) && invoker.is_64_bit_browser) {
           shared_libraries = [ "//chrome/android:monochrome_64${_suffix}" ]
-          if ((build_apk_secondary_abi && invoker.include_32_bit_webview) ||
-              android_64bit_browser) {
+          if (build_apk_secondary_abi && invoker.include_32_bit_webview) {
             secondary_abi_shared_libraries = [ "//android_webview:monochrome_64${_suffix}($android_secondary_abi_toolchain)" ]
           }
         } else {

chrome/android/monochrome_android_manifest_jinja_variables.gni

@@ -2,16 +2,10 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//chrome/android/chrome_public_apk_tmpl.gni")
-
 use_32bit_abi_jinja_variable = "use32bitAbi=android:use32bitAbi=\"true\""
 
 monochrome_android_manifest_jinja_variables = [
   "min_sdk_version=24",
   "sandboxed_service_exported=true",
+  use_32bit_abi_jinja_variable,
 ]
-
-if (!android_64bit_browser) {
-  monochrome_android_manifest_jinja_variables +=
-      [ use_32bit_abi_jinja_variable ]
-}

chrome/android/trichrome.gni

@@ -29,12 +29,9 @@ trichrome_jinja_variables = [
   "trichrome_library=$trichrome_library_package",
   "trichrome_version=$trichrome_version_code",
   "trichrome_certdigest=$trichrome_certdigest",
+  "use32bitAbi=android:use32bitAbi=\"true\"",
 ]
 
-if (!android_64bit_browser) {
-  trichrome_jinja_variables += [ "use32bitAbi=android:use32bitAbi=\"true\"" ]
-}
-
 template("trichrome_library_apk_tmpl") {
   android_apk(target_name) {
     forward_variables_from(invoker,
@@ -81,18 +78,11 @@ template("trichrome_library_apk_tmpl") {
       # opposite-bitness placeholder library to ensure that the library is
       # treated as multiarch and gets its Java code precompiled for both
       # architectures.
-      if (android_64bit_browser) {
-        shared_libraries = [ "//chrome/android:monochrome" ]
-        if (build_apk_secondary_abi) {
-          secondary_native_lib_placeholders = [ "libdummy.so" ]
-        }
-      } else {
       native_lib_placeholders = [ "libdummy.so" ]
       if (build_apk_secondary_abi) {
         secondary_abi_shared_libraries =
             [ "//chrome/android:monochrome_secondary_abi_lib" ]
       }
-      }
     } else {
       shared_libraries = [ "//chrome/android:monochrome" ]
     }