Revert of media: Simplify CdmHostFile(s)

content/common/media/cdm_host_files.cc

Index: content/common/media/cdm_host_files.cc
diff --git a/content/common/media/cdm_host_files.cc b/content/common/media/cdm_host_files.cc
index 7d0c0174c663976c2c7f88408ee812b8d5360299..1310403ecc596850a28f24dcbde20abff5c65b04 100644
--- a/content/common/media/cdm_host_files.cc
+++ b/content/common/media/cdm_host_files.cc
@@ -21,6 +21,7 @@
 #include "content/common/media/cdm_host_file.h"
 #include "content/public/common/cdm_info.h"
 #include "content/public/common/content_client.h"
+#include "media/base/media_switches.h"
 #include "media/cdm/api/content_decryption_module_ext.h"
 #include "media/cdm/cdm_paths.h"
 
@@ -34,6 +35,11 @@
 namespace content {
 
 namespace {
+
+bool IgnoreMissingCdmHostFile() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kIgnoreMissingCdmHostFile);
+}
 
 // TODO(xhwang): Move this to a common place if needed.
 const base::FilePath::CharType kSignatureFileExtension[] =
@@ -114,7 +120,12 @@
 
   std::unique_ptr<CdmHostFiles> cdm_host_files =
       base::MakeUnique<CdmHostFiles>();
-  cdm_host_files->OpenFilesForAllRegisteredCdms();
+  if (!cdm_host_files->OpenFilesForAllRegisteredCdms()) {
+    DVLOG(1) << __func__ << " failed.";
+    cdm_host_files.reset();
+    return;
+  }
+
   g_cdm_host_files.Get().reset(cdm_host_files.release());
 }
 
@@ -130,7 +141,11 @@
   DVLOG(1) << __func__;
   std::unique_ptr<CdmHostFiles> cdm_host_files =
       base::MakeUnique<CdmHostFiles>();
-  cdm_host_files->OpenFiles(cdm_adapter_path);
+  if (!cdm_host_files->OpenFiles(cdm_adapter_path)) {
+    cdm_host_files.reset();
+    return nullptr;
+  }
+
   return cdm_host_files;
 }
 
@@ -178,50 +193,61 @@
   // Fills |cdm_host_files| with common and CDM specific files for
   // |cdm_adapter_path|.
   std::vector<cdm::HostFile> cdm_host_files;
-  TakePlatformFiles(cdm_adapter_path, &cdm_host_files);
-
-  // All remaining files will be closed (e.g. files for other CDMs).
-  CloseAllFiles();
-
-  // std::vector::data() is not guaranteed to be nullptr when empty().
-  const cdm::HostFile* cdm_host_files_ptr =
-      cdm_host_files.empty() ? nullptr : cdm_host_files.data();
+  if (!TakePlatformFiles(cdm_adapter_path, &cdm_host_files)) {
+    DVLOG(1) << "Failed to take platform files.";
+    CloseAllFiles();
+    return true;
+  }
 
   // Call |verify_cdm_host_func| on the CDM with |cdm_host_files|. Note that
   // the ownership of these files are transferred to the CDM, which will close
   // the files immediately after use.
   DVLOG(1) << __func__ << ": Calling " << kVerifyCdmHostFuncName << "().";
-  if (!verify_cdm_host_func(cdm_host_files_ptr, cdm_host_files.size())) {
+  if (!verify_cdm_host_func(cdm_host_files.data(), cdm_host_files.size())) {
     DVLOG(1) << "Failed to verify CDM host.";
+    CloseAllFiles();
     return false;
   }
 
   // Close all files not passed to the CDM.
+  CloseAllFiles();
   return true;
 }
 
 #if defined(POSIX_WITH_ZYGOTE)
-void CdmHostFiles::OpenFilesForAllRegisteredCdms() {
+bool CdmHostFiles::OpenFilesForAllRegisteredCdms() {
   std::vector<base::FilePath> cdm_adapter_paths;
   GetRegisteredCdms(&cdm_adapter_paths);
   if (cdm_adapter_paths.empty()) {
     DVLOG(1) << "No CDM registered.";
-    return;
-  }
-
-  for (auto& cdm_adapter_path : cdm_adapter_paths)
-    OpenCdmFiles(cdm_adapter_path);
-
-  OpenCommonFiles();
-}
-#endif
-
-void CdmHostFiles::OpenFiles(const base::FilePath& cdm_adapter_path) {
-  OpenCdmFiles(cdm_adapter_path);
-  OpenCommonFiles();
-}
-
-void CdmHostFiles::OpenCommonFiles() {
+    return false;
+  }
+
+  // Ignore
+  for (auto& cdm_adapter_path : cdm_adapter_paths) {
+    bool result = OpenCdmFiles(cdm_adapter_path);
+    if (!result)
+      DVLOG(1) << "CDM files cannot be opened for " << cdm_adapter_path.value();
+    // Ignore the failure and try other registered CDM.
+  }
+
+  if (cdm_specific_files_map_.empty()) {
+    DVLOG(1) << "CDM specific files cannot be opened for any registered CDM.";
+    return false;
+  }
+
+  return OpenCommonFiles();
+}
+#endif
+
+bool CdmHostFiles::OpenFiles(const base::FilePath& cdm_adapter_path) {
+  if (!OpenCdmFiles(cdm_adapter_path))
+    return false;
+
+  return OpenCommonFiles();
+}
+
+bool CdmHostFiles::OpenCommonFiles() {
   DCHECK(common_files_.empty());
 
   std::vector<CdmHostFilePath> cdm_host_file_paths;
@@ -229,21 +255,34 @@
                                                   &cdm_host_file_paths);
 
   for (const CdmHostFilePath& value : cdm_host_file_paths) {
-    common_files_.push_back(
-        CdmHostFile::Create(value.file_path, value.sig_file_path));
-  }
-}
-
-void CdmHostFiles::OpenCdmFiles(const base::FilePath& cdm_adapter_path) {
+    std::unique_ptr<CdmHostFile> cdm_host_file =
+        CdmHostFile::Create(value.file_path, value.sig_file_path);
+    if (cdm_host_file) {
+      common_files_.push_back(std::move(cdm_host_file));
+      continue;
+    }
+
+    if (!IgnoreMissingCdmHostFile())
+      return false;
+  }
+
+  return true;
+}
+
+bool CdmHostFiles::OpenCdmFiles(const base::FilePath& cdm_adapter_path) {
   DCHECK(!cdm_adapter_path.empty());
   DCHECK(!cdm_specific_files_map_.count(cdm_adapter_path));
 
   std::unique_ptr<CdmHostFile> cdm_adapter_file =
       CdmHostFile::Create(cdm_adapter_path, GetSigFilePath(cdm_adapter_path));
+  if (!cdm_adapter_file)
+    return false;
 
   base::FilePath cdm_path = GetCdmPath(cdm_adapter_path);
   std::unique_ptr<CdmHostFile> cdm_file =
       CdmHostFile::Create(cdm_path, GetSigFilePath(cdm_path));
+  if (!cdm_file)
+    return false;
 
   ScopedFileVector cdm_specific_files;
   cdm_specific_files.reserve(2);
@@ -251,26 +290,38 @@
   cdm_specific_files.push_back(std::move(cdm_file));
 
   cdm_specific_files_map_[cdm_adapter_path] = std::move(cdm_specific_files);
-}
-
-void CdmHostFiles::TakePlatformFiles(
+  return true;
+}
+
+bool CdmHostFiles::TakePlatformFiles(
     const base::FilePath& cdm_adapter_path,
     std::vector<cdm::HostFile>* cdm_host_files) {
   DCHECK(cdm_host_files->empty());
 
+  if (!IgnoreMissingCdmHostFile())
+    DCHECK(!common_files_.empty());
+
+  // Check whether CDM specific files exist.
+  const auto& iter = cdm_specific_files_map_.find(cdm_adapter_path);
+  if (iter == cdm_specific_files_map_.end()) {
+    // This could happen on Linux where CDM files fail to open for Foo CDM, but
+    // now we hit Bar CDM.
+    DVLOG(1) << "No CDM specific files for " << cdm_adapter_path.value();
+    return false;
+  }
+
+  const ScopedFileVector& cdm_specific_files = iter->second;
+
+  cdm_host_files->reserve(common_files_.size() + cdm_specific_files.size());
+
   // Populate an array of cdm::HostFile.
   for (const auto& file : common_files_)
     cdm_host_files->push_back(file->TakePlatformFile());
 
-  // Check whether CDM specific files exist.
-  const auto& iter = cdm_specific_files_map_.find(cdm_adapter_path);
-  if (iter == cdm_specific_files_map_.end()) {
-    NOTREACHED() << "No CDM specific files for " << cdm_adapter_path.value();
-  } else {
-    const ScopedFileVector& cdm_specific_files = iter->second;
-    for (const auto& file : cdm_specific_files)
-      cdm_host_files->push_back(file->TakePlatformFile());
-  }
+  for (const auto& file : cdm_specific_files)
+    cdm_host_files->push_back(file->TakePlatformFile());
+
+  return true;
 }
 
 void CdmHostFiles::CloseAllFiles() {