Revert of Parse USB interface association descriptors. (patchset #3 id:100001 of https://codereview.chromium.org/1568673002/ )

Reason for revert:
http://crbug.com/586824

Makes Chrome hang when using USB devices.

Original issue's description:
> Parse USB interface association descriptors.
>
> USB interface association descriptors are used to combine multiple
> interfaces into a single functional group. This patch adds support for
> parsing them out of the |extra_data| field left by libusb's parsing of
> configuration, interface and endpoint descriptors. The resulting
> association is then represented by setting the |first_interface| field
> of each interface in a function to the |interface_number| of the first
> interface in the function.
>
> WebUSB will use these associations to set permissions for an entire
> function with a single descriptor.
>

TBR=rockot@chromium.org,pfeldman@chromium.org,stevenjb@chromium.org,reillyg@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=492204, 586824

Review URL: https://codereview.chromium.org/1697863003

Cr-Commit-Position: refs/heads/master@{#375392}

4 files changed, 1 insertions, 163 deletions

diff --git a/device/usb/usb_descriptors.cc b/device/usb/usb_descriptors.cc
index 22414d7..6defda8 100644
--- a/device/usb/usb_descriptors.cc
+++ b/device/usb/usb_descriptors.cc
@@ -7,7 +7,6 @@
 #include <stddef.h>
 
 #include <algorithm>
-#include <vector>
 
 #include "base/barrier_closure.h"
 #include "base/bind.h"
@@ -27,42 +26,6 @@ const uint8_t kStringDescriptorType = 0x03;
 
 const int kControlTransferTimeout = 60000;  // 1 minute
 
-struct UsbInterfaceAssociationDescriptor {
-  UsbInterfaceAssociationDescriptor(uint8_t first_interface,
-                                    uint8_t interface_count)
-      : first_interface(first_interface), interface_count(interface_count) {}
-
-  bool operator<(const UsbInterfaceAssociationDescriptor& other) const {
-    return first_interface < other.first_interface;
-  }
-
-  uint8_t first_interface;
-  uint8_t interface_count;
-};
-
-void ParseInterfaceAssociationDescriptors(
-    const std::vector<uint8_t>& buffer,
-    std::vector<UsbInterfaceAssociationDescriptor>* functions) {
-  const uint8_t kInterfaceAssociationDescriptorType = 11;
-  const uint8_t kInterfaceAssociationDescriptorLength = 8;
-  std::vector<uint8_t>::const_iterator it = buffer.begin();
-
-  while (it != buffer.end()) {
-    // All descriptors must be at least 2 byte which means the length and type
-    // are safe to read.
-    if (std::distance(it, buffer.end()) < 2)
-      return;
-    uint8_t length = it[0];
-    if (length > std::distance(it, buffer.end()))
-      return;
-    if (it[1] == kInterfaceAssociationDescriptorType &&
-        length == kInterfaceAssociationDescriptorLength) {
-      functions->push_back(UsbInterfaceAssociationDescriptor(it[2], it[3]));
-    }
-    std::advance(it, length);
-  }
-}
-
 void StoreStringDescriptor(IndexMap::iterator it,
                            const base::Closure& callback,
                            const base::string16& string) {
@@ -150,8 +113,7 @@ UsbInterfaceDescriptor::UsbInterfaceDescriptor(uint8_t interface_number,
       alternate_setting(alternate_setting),
       interface_class(interface_class),
       interface_subclass(interface_subclass),
-      interface_protocol(interface_protocol),
-      first_interface(interface_number) {}
+      interface_protocol(interface_protocol) {}
 
 UsbInterfaceDescriptor::~UsbInterfaceDescriptor() = default;
 
@@ -166,47 +128,6 @@ UsbConfigDescriptor::UsbConfigDescriptor(uint8_t configuration_value,
 
 UsbConfigDescriptor::~UsbConfigDescriptor() = default;
 
-void UsbConfigDescriptor::AssignFirstInterfaceNumbers() {
-  std::vector<UsbInterfaceAssociationDescriptor> functions;
-  ParseInterfaceAssociationDescriptors(extra_data, &functions);
-  for (const auto& interface : interfaces) {
-    ParseInterfaceAssociationDescriptors(interface.extra_data, &functions);
-    for (const auto& endpoint : interface.endpoints)
-      ParseInterfaceAssociationDescriptors(endpoint.extra_data, &functions);
-  }
-
-  // libusb has collected interface association descriptors in the |extra_data|
-  // fields of other descriptor types. This may have disturbed their order
-  // but sorting by the bFirstInterface should fix it.
-  std::sort(functions.begin(), functions.end());
-
-  uint8_t remaining_interfaces = 0;
-  auto function_it = functions.cbegin();
-  for (auto interface_it = interfaces.begin(); interface_it != interfaces.end();
-       ++interface_it) {
-    if (remaining_interfaces > 0) {
-      // Continuation of a previous function. Tag all alternate interfaces
-      // (which are guaranteed to be contiguous).
-      for (uint8_t interface_number = interface_it->interface_number;
-           interface_it != interfaces.end() &&
-           interface_it->interface_number == interface_number;
-           ++interface_it) {
-        interface_it->first_interface = function_it->first_interface;
-      }
-      if (--remaining_interfaces == 0)
-        ++function_it;
-    } else if (function_it != functions.end() &&
-               interface_it->interface_number == function_it->first_interface) {
-      // Start of a new function.
-      interface_it->first_interface = function_it->first_interface;
-      remaining_interfaces = function_it->interface_count - 1;
-    } else {
-      // Unassociated interfaces already have |first_interface| set to
-      // |interface_number|.
-    }
-  }
-}
-
 bool ParseUsbStringDescriptor(const std::vector<uint8_t>& descriptor,
                               base::string16* output) {
   if (descriptor.size() < 2 || descriptor[1] != kStringDescriptorType)
diff --git a/device/usb/usb_descriptors.h b/device/usb/usb_descriptors.h
index a1414154..c99a6de 100644
--- a/device/usb/usb_descriptors.h
+++ b/device/usb/usb_descriptors.h
@@ -85,8 +85,6 @@ struct UsbInterfaceDescriptor {
   uint8_t interface_protocol;
   std::vector<UsbEndpointDescriptor> endpoints;
   std::vector<uint8_t> extra_data;
-  // First interface of the function to which this interface belongs.
-  uint8_t first_interface;
 };
 
 struct UsbConfigDescriptor {
@@ -97,10 +95,6 @@ struct UsbConfigDescriptor {
   UsbConfigDescriptor() = delete;
   ~UsbConfigDescriptor();
 
-  // Scans through |extra_data| for interface association descriptors and
-  // populates |first_interface| for each interface in this configuration.
-  void AssignFirstInterfaceNumbers();
-
   uint8_t configuration_value;
   bool self_powered;
   bool remote_wakeup;
diff --git a/device/usb/usb_descriptors_unittest.cc b/device/usb/usb_descriptors_unittest.cc
index 5bc2943..402304f 100644
--- a/device/usb/usb_descriptors_unittest.cc
+++ b/device/usb/usb_descriptors_unittest.cc
@@ -32,81 +32,6 @@ void ExpectStringDescriptors(
 
 class UsbDescriptorsTest : public ::testing::Test {};
 
-TEST_F(UsbDescriptorsTest, NoInterfaceAssociations) {
-  UsbConfigDescriptor config(1, false, false, 0);
-  config.interfaces.emplace_back(0, 0, 255, 255, 255);
-  config.interfaces.emplace_back(0, 1, 255, 255, 255);
-  config.interfaces.emplace_back(1, 0, 255, 255, 255);
-  config.AssignFirstInterfaceNumbers();
-
-  EXPECT_EQ(0, config.interfaces[0].first_interface);
-  EXPECT_EQ(0, config.interfaces[1].first_interface);
-  EXPECT_EQ(1, config.interfaces[2].first_interface);
-}
-
-TEST_F(UsbDescriptorsTest, InterfaceAssociations) {
-  // Links interfaces 0 and 1 into a single function.
-  static const uint8_t kIAD1[] = {0x08, 0x0b, 0x00, 0x02,
-                                  0xff, 0xff, 0xff, 0x00};
-  // Only references a single interface, 2.
-  static const uint8_t kIAD2[] = {0x08, 0x0b, 0x02, 0x01,
-                                  0xff, 0xff, 0xff, 0x00};
-  // Malformed. References interface 3 but bInterfaceCount is 0.
-  static const uint8_t kIAD3[] = {0x08, 0x0b, 0x03, 0x00,
-                                  0xff, 0xff, 0xff, 0x00};
-  // Malformed. References an indefined interface.
-  static const uint8_t kIAD4[] = {0x08, 0x0b, 0x07, 0x00,
-                                  0xff, 0xff, 0xff, 0x00};
-  // Links interfaces 4 and 5 into a single function.
-  static const uint8_t kIAD5[] = {0x08, 0x0b, 0x04, 0x01,
-                                  0xff, 0xff, 0xff, 0x00};
-
-  UsbConfigDescriptor config(1, false, false, 0);
-  config.extra_data.assign(kIAD1, kIAD1 + sizeof(kIAD1));
-  config.extra_data.insert(config.extra_data.end(), kIAD2,
-                           kIAD2 + sizeof(kIAD2));
-  config.interfaces.emplace_back(0, 0, 255, 255, 255);
-  config.interfaces.emplace_back(1, 0, 255, 255, 255);
-  UsbInterfaceDescriptor iface1a(1, 1, 255, 255, 255);
-  iface1a.extra_data.assign(kIAD3, kIAD3 + sizeof(kIAD3));
-  config.interfaces.push_back(std::move(iface1a));
-  config.interfaces.emplace_back(2, 0, 255, 255, 255);
-  config.interfaces.emplace_back(3, 0, 255, 255, 255);
-  UsbInterfaceDescriptor iface4(4, 0, 255, 255, 255);
-  iface4.extra_data.assign(kIAD4, kIAD4 + sizeof(kIAD4));
-  iface4.extra_data.insert(iface4.extra_data.end(), kIAD5,
-                           kIAD5 + sizeof(kIAD5));
-  config.interfaces.push_back(std::move(iface4));
-  config.interfaces.emplace_back(5, 0, 255, 255, 255);
-  config.AssignFirstInterfaceNumbers();
-
-  EXPECT_EQ(0, config.interfaces[0].first_interface);
-  EXPECT_EQ(0, config.interfaces[1].first_interface);
-  EXPECT_EQ(0, config.interfaces[2].first_interface);
-  EXPECT_EQ(2, config.interfaces[3].first_interface);
-  EXPECT_EQ(3, config.interfaces[4].first_interface);
-  EXPECT_EQ(4, config.interfaces[5].first_interface);
-  EXPECT_EQ(4, config.interfaces[5].first_interface);
-}
-
-TEST_F(UsbDescriptorsTest, CorruptInterfaceAssociations) {
-  {
-    // Descriptor is too short.
-    static const uint8_t kIAD[] = {0x01};
-    UsbConfigDescriptor config(1, false, false, 0);
-    config.extra_data.assign(kIAD, kIAD + sizeof(kIAD));
-    config.AssignFirstInterfaceNumbers();
-  }
-  {
-    // Descriptor is too long.
-    static const uint8_t kIAD[] = {0x09, 0x0b, 0x00, 0x00,
-                                   0x00, 0x00, 0x00, 0x00};
-    UsbConfigDescriptor config(1, false, false, 0);
-    config.extra_data.assign(kIAD, kIAD + sizeof(kIAD));
-    config.AssignFirstInterfaceNumbers();
-  }
-}
-
 TEST_F(UsbDescriptorsTest, StringDescriptor) {
   static const uint8_t kBuffer[] = {0x1a, 0x03, 'H', 0, 'e', 0, 'l', 0, 'l', 0,
                                     'o',  0,    ' ', 0, 'w', 0, 'o', 0, 'r', 0,
diff --git a/device/usb/usb_device_impl.cc b/device/usb/usb_device_impl.cc
index 118416d..1a8bedf 100644
--- a/device/usb/usb_device_impl.cc
+++ b/device/usb/usb_device_impl.cc
@@ -135,8 +135,6 @@ void ConvertConfigDescriptor(const libusb_config_descriptor* platform_config,
   configuration->extra_data.assign(
       platform_config->extra,
       platform_config->extra + platform_config->extra_length);
-
-  configuration->AssignFirstInterfaceNumbers();
 }
 
 }  // namespace