Use cdm_platform_specific_path from cdm_paths.gni

Rather than duplicate the logic in cdm_paths.cc, pass
cdm_platform_specific_path from cdm_paths.gni using BUILDFLAGS.

Bug: 971433
Test: EME browser_tests pass
Change-Id: I0cdfb768b36e991fc407291093ee00bf3cd5cffa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1747197
Commit-Queue: John Rummell <jrummell@chromium.org>
Reviewed-by: Xiaohan Wang <xhwang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#687369}

media/BUILD.gn

@@ -8,6 +8,7 @@ import("//build/config/arm.gni")
 import("//build/config/features.gni")
 import("//build/config/linux/pkg_config.gni")
 import("//build/config/ui.gni")
+import("//media/cdm/library_cdm/cdm_paths.gni")
 import("//media/media_options.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
 import("//testing/test.gni")
@@ -17,7 +18,8 @@ buildflag_header("media_buildflags") {
   header = "media_buildflags.h"
 
   flags = [
-    "ALTERNATE_CDM_STORAGE_ID_KEY=$alternate_cdm_storage_id_key",
+    "ALTERNATE_CDM_STORAGE_ID_KEY=\"$alternate_cdm_storage_id_key\"",
+    "CDM_PLATFORM_SPECIFIC_PATH=\"$cdm_platform_specific_path\"",
     "ENABLE_AC3_EAC3_AUDIO_DEMUXING=$enable_ac3_eac3_audio_demuxing",
     "ENABLE_CBCS_ENCRYPTION_SCHEME=$enable_cbcs_encryption_scheme",
     "ENABLE_CDM_HOST_VERIFICATION=$enable_cdm_host_verification",

media/cdm/BUILD.gn

@@ -113,6 +113,7 @@ static_library("cdm_paths") {
   ]
   deps = [
     "//base",
+    "//media:media_buildflags",
   ]
 }
 
@@ -148,6 +149,7 @@ source_set("unit_tests") {
   if (enable_library_cdms) {
     sources += [
       "cdm_adapter_unittest.cc",
+      "cdm_paths_unittest.cc",
       "external_clear_key_test_helper.cc",
       "external_clear_key_test_helper.h",
       "mock_helpers.cc",

media/cdm/cdm_paths.cc

@@ -6,7 +6,7 @@
 
 #include <string>
 
-#include "build/build_config.h"
+#include "media/media_buildflags.h"
 
 namespace media {
 
@@ -24,60 +24,16 @@ const base::Token kClearKeyCdmDifferentGuid{0xc3914773474bdb02ull,
 // this ID is based on the pepper plugin MIME type.
 const char kClearKeyCdmFileSystemId[] = "application_x-ppapi-clearkey-cdm";
 
-// Note: This file must be in sync with cdm_paths.gni.
-// TODO(xhwang): Improve how we enable platform specific path. See
-// http://crbug.com/468584
-#if (defined(OS_MACOSX) || defined(OS_WIN)) && \
-    (defined(ARCH_CPU_X86) || defined(ARCH_CPU_X86_64))
-#define CDM_USE_PLATFORM_SPECIFIC_PATH
-#endif
-
-#if defined(CDM_USE_PLATFORM_SPECIFIC_PATH)
-
-// Special path used in chrome components.
-const char kPlatformSpecific[] = "_platform_specific";
-
-// Name of the component platform in the manifest.
-const char kComponentPlatform[] =
-#if defined(OS_MACOSX)
-    "mac";
-#elif defined(OS_WIN)
-    "win";
-#elif defined(OS_CHROMEOS)
-    "cros";
-#elif defined(OS_LINUX)
-    "linux";
-#else
-    "unsupported_platform";
-#endif
-
-// Name of the component architecture in the manifest.
-const char kComponentArch[] =
-#if defined(ARCH_CPU_X86)
-    "x86";
-#elif defined(ARCH_CPU_X86_64)
-    "x64";
-#elif defined(ARCH_CPU_ARMEL)
-    "arm";
-#else
-    "unsupported_arch";
-#endif
-
 base::FilePath GetPlatformSpecificDirectory(const std::string& cdm_base_path) {
-  base::FilePath path;
-  const std::string kPlatformArch =
-      std::string(kComponentPlatform) + "_" + kComponentArch;
-  return path.AppendASCII(cdm_base_path)
-      .AppendASCII(kPlatformSpecific)
-      .AppendASCII(kPlatformArch);
-}
-
-#else  // defined(CDM_USE_PLATFORM_SPECIFIC_PATH)
+  // CDM_PLATFORM_SPECIFIC_PATH is specified in cdm_paths.gni.
+  const std::string kPlatformSpecific = BUILDFLAG(CDM_PLATFORM_SPECIFIC_PATH);
+  if (kPlatformSpecific.empty())
+    return base::FilePath();
 
-base::FilePath GetPlatformSpecificDirectory(const std::string& cdm_base_path) {
-  return base::FilePath();
+  return base::FilePath()
+      .AppendASCII(cdm_base_path)
+      .AppendASCII(kPlatformSpecific)
+      .NormalizePathSeparators();
 }
 
-#endif  // defined(CDM_USE_PLATFORM_SPECIFIC_PATH)
-
 }  // namespace media

media/cdm/cdm_paths_unittest.cc

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/cdm/cdm_paths.h"
+
+#include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
+#include "base/strings/utf_string_conversions.h"
+#include "build/build_config.h"
+#include "media/media_buildflags.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+// Only verify platform specific path where CDMs are Chrome components.
+#if (defined(OS_MACOSX) || defined(OS_WIN)) && \
+    (defined(ARCH_CPU_X86) || defined(ARCH_CPU_X86_64))
+#define CDM_USE_PLATFORM_SPECIFIC_PATH
+#endif
+
+namespace media {
+
+namespace {
+
+#if defined(CDM_USE_PLATFORM_SPECIFIC_PATH)
+
+// Special path used in chrome components.
+const char kPlatformSpecific[] = "_platform_specific";
+
+// Name of the component platform.
+const char kComponentPlatform[] =
+#if defined(OS_MACOSX)
+    "mac";
+#elif defined(OS_WIN)
+    "win";
+#elif defined(OS_CHROMEOS)
+    "cros";
+#elif defined(OS_LINUX)
+    "linux";
+#else
+    "unsupported_platform";
+#endif
+
+// Name of the component architecture.
+const char kComponentArch[] =
+#if defined(ARCH_CPU_X86)
+    "x86";
+#elif defined(ARCH_CPU_X86_64)
+    "x64";
+#elif defined(ARCH_CPU_ARMEL)
+    "arm";
+#else
+    "unsupported_arch";
+#endif
+
+base::FilePath GetExpectedPlatformSpecificDirectory(
+    const std::string& base_path) {
+  base::FilePath path;
+  const std::string kPlatformArch =
+      std::string(kComponentPlatform) + "_" + kComponentArch;
+  return path.AppendASCII(base_path)
+      .AppendASCII(kPlatformSpecific)
+      .AppendASCII(kPlatformArch);
+}
+
+#else
+
+// If the CDM is not a component, it has no platform specific path.
+base::FilePath GetExpectedPlatformSpecificDirectory(
+    const std::string& base_path) {
+  return base::FilePath();
+}
+
+#endif  // defined(CDM_USE_PLATFORM_SPECIFIC_PATH)
+
+std::string GetFlag() {
+  return BUILDFLAG(CDM_PLATFORM_SPECIFIC_PATH);
+}
+
+}  // namespace
+
+TEST(CdmPathsTest, FlagSpecified) {
+#if defined(CDM_USE_PLATFORM_SPECIFIC_PATH)
+  EXPECT_FALSE(GetFlag().empty());
+#else
+  EXPECT_TRUE(GetFlag().empty());
+#endif
+}
+
+TEST(CdmPathsTest, Prefix) {
+  const char kPrefix[] = "prefix";
+  auto path = GetPlatformSpecificDirectory(kPrefix);
+
+#if defined(CDM_USE_PLATFORM_SPECIFIC_PATH)
+  EXPECT_TRUE(base::StartsWith(path.MaybeAsASCII(), kPrefix,
+                               base::CompareCase::SENSITIVE));
+#else
+  EXPECT_TRUE(path.MaybeAsASCII().empty());
+#endif
+}
+
+TEST(CdmPathsTest, Expected) {
+  const char kPrefix[] = "cdm";
+  EXPECT_EQ(GetExpectedPlatformSpecificDirectory(kPrefix),
+            GetPlatformSpecificDirectory(kPrefix));
+}
+
+}  // namespace media

media/cdm/library_cdm/cdm_paths.gni

@@ -7,8 +7,6 @@
 # Naming and folder structure below are following the recommendation for Chrome
 # components. Component-updated CDMs must follow the same recommendation.
 
-# Note: This file must be in sync with cdm_paths.cc
-
 # OS name for components is close to "target_os" but has some differences.
 # Explicitly define what we use to avoid confusion.
 if (is_chromeos) {
@@ -29,21 +27,21 @@ if (current_cpu == "x86" || current_cpu == "x64" || current_cpu == "arm") {
   component_arch = "unsupported_arch"
 }
 
-# Only enable platform specific path for Win and Mac, where CDMs are Chrome
-# components.
-# TODO(xhwang): Improve how we enable platform specific path. See
-# http://crbug.com/468584
+# Only enable platform specific path where CDMs are Chrome components.
+# Note: |cdm_platform_specific_path| is exported as a BUILDFLAG to cdm_paths.cc.
 if ((is_win || is_mac) && (current_cpu == "x86" || current_cpu == "x64")) {
-  _platform_specific_path =
+  cdm_platform_specific_path =
       "_platform_specific/$component_os" + "_" + "$component_arch"
 
   # Path of Clear Key and Widevine CDMs relative to the output dir.
-  clearkey_cdm_path = "ClearKeyCdm/$_platform_specific_path"
-  widevine_cdm_path = "WidevineCdm/$_platform_specific_path"
+  clearkey_cdm_path = "ClearKeyCdm/$cdm_platform_specific_path"
+  widevine_cdm_path = "WidevineCdm/$cdm_platform_specific_path"
 } else if (is_fuchsia) {
+  cdm_platform_specific_path = ""
   clearkey_cdm_path = "lib"
   widevine_cdm_path = "lib"
 } else {
+  cdm_platform_specific_path = ""
   clearkey_cdm_path = "."
   widevine_cdm_path = "."
 }