diff --git a/BUILD.gn b/BUILD.gn
index 924e83218a..0a47cd7841 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -470,6 +470,8 @@ source_set("libtint_spv_reader_src") {
     "src/reader/spirv/parser.h",
     "src/reader/spirv/parser_impl.cc",
     "src/reader/spirv/parser_impl.h",
+    "src/reader/spirv/usage.cc",
+    "src/reader/spirv/usage.h",
   ]
 
   deps = [
@@ -855,6 +857,7 @@ source_set("tint_unittests_spv_reader_src") {
     "src/reader/spirv/parser_test.cc",
     "src/reader/spirv/spirv_tools_helpers_test.cc",
     "src/reader/spirv/spirv_tools_helpers_test.h",
+    "src/reader/spirv/usage_test.cc",
   ]
 
   configs += [
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 717a6303dd..99e56366c4 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -273,6 +273,8 @@ if(${TINT_BUILD_SPV_READER})
     reader/spirv/parser.h
     reader/spirv/parser_impl.cc
     reader/spirv/parser_impl.h
+    reader/spirv/usage.cc
+    reader/spirv/usage.h
   )
 endif()
 
@@ -459,6 +461,7 @@ if(${TINT_BUILD_SPV_READER})
     reader/spirv/parser_test.cc
     reader/spirv/spirv_tools_helpers_test.cc
     reader/spirv/spirv_tools_helpers_test.h
+    reader/spirv/usage_test.cc
   )
 endif()
 
diff --git a/src/reader/spirv/usage.cc b/src/reader/spirv/usage.cc
new file mode 100644
index 0000000000..23635e16e8
--- /dev/null
+++ b/src/reader/spirv/usage.cc
@@ -0,0 +1,186 @@
+// Copyright 2020 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "src/reader/spirv/usage.h"
+
+namespace tint {
+namespace reader {
+namespace spirv {
+
+Usage::Usage() {}
+Usage::Usage(const Usage& other) = default;
+Usage::~Usage() = default;
+
+std::ostream& Usage::operator<<(std::ostream& out) const {
+  out << "Usage(";
+  if (IsSampler()) {
+    out << "Sampler(";
+    if (is_comparison_sampler_) {
+      out << " comparison";
+    }
+    out << " )";
+  }
+  if (IsTexture()) {
+    out << "Texture(";
+    if (is_sampled_) {
+      out << " is_sampled";
+    }
+    if (is_multisampled_) {
+      out << " ms";
+    }
+    if (is_depth_) {
+      out << " depth";
+    }
+    if (is_storage_read_) {
+      out << " read";
+    }
+    if (is_storage_write_) {
+      out << " write";
+    }
+    out << " )";
+  }
+  out << ")";
+  return out;
+}
+
+bool Usage::IsValid() const {
+  // Check sampler state internal consistency.
+  if (is_comparison_sampler_ && !is_sampler_) {
+    return false;
+  }
+
+  // Check texture state.
+  // |is_texture_| is implied by any of the later texture-based properties.
+  if ((IsStorageTexture() || is_sampled_ || is_multisampled_ || is_depth_) &&
+      !is_texture_) {
+    return false;
+  }
+  if (is_texture_) {
+    // Multisampled implies sampled.
+    if (is_multisampled_) {
+      if (!is_sampled_) {
+        return false;
+      }
+    }
+    // Depth implies sampled.
+    if (is_depth_) {
+      if (!is_sampled_) {
+        return false;
+      }
+    }
+
+    // Sampled can't be storage.
+    if (is_sampled_) {
+      if (IsStorageTexture()) {
+        return false;
+      }
+    }
+
+    // Storage can't be sampled.
+    if (IsStorageTexture()) {
+      if (is_sampled_) {
+        return false;
+      }
+    }
+    // Storage texture can't also be a sampler.
+    if (IsStorageTexture()) {
+      if (is_sampler_) {
+        return false;
+      }
+    }
+
+    // Can't be both read and write.  This is a restriction in WebGPU.
+    if (is_storage_read_ && is_storage_write_) {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool Usage::IsComplete() const {
+  if (!IsValid()) {
+    return false;
+  }
+  if (IsSampler()) {
+    return true;
+  }
+  if (IsTexture()) {
+    return is_sampled_ || IsStorageTexture();
+  }
+  return false;
+}
+
+bool Usage::operator==(const Usage& other) const {
+  return is_sampler_ == other.is_sampler_ &&
+         is_comparison_sampler_ == other.is_comparison_sampler_ &&
+         is_texture_ == other.is_texture_ && is_sampled_ == other.is_sampled_ &&
+         is_multisampled_ == other.is_multisampled_ &&
+         is_depth_ == other.is_depth_ &&
+         is_storage_read_ == other.is_storage_read_ &&
+         is_storage_write_ == other.is_storage_write_;
+}
+
+void Usage::Add(const Usage& other) {
+  is_sampler_ = is_sampler_ || other.is_sampler_;
+  is_comparison_sampler_ =
+      is_comparison_sampler_ || other.is_comparison_sampler_;
+  is_texture_ = is_texture_ || other.is_texture_;
+  is_sampled_ = is_sampled_ || other.is_sampled_;
+  is_multisampled_ = is_multisampled_ || other.is_multisampled_;
+  is_depth_ = is_depth_ || other.is_depth_;
+  is_storage_read_ = is_storage_read_ || other.is_storage_read_;
+  is_storage_write_ = is_storage_write_ || other.is_storage_write_;
+}
+
+void Usage::AddSampler() {
+  is_sampler_ = true;
+}
+
+void Usage::AddComparisonSampler() {
+  AddSampler();
+  is_comparison_sampler_ = true;
+}
+
+void Usage::AddTexture() {
+  is_texture_ = true;
+}
+
+void Usage::AddStorageReadTexture() {
+  AddTexture();
+  is_storage_read_ = true;
+}
+
+void Usage::AddStorageWriteTexture() {
+  AddTexture();
+  is_storage_write_ = true;
+}
+
+void Usage::AddSampledTexture() {
+  AddTexture();
+  is_sampled_ = true;
+}
+
+void Usage::AddMultisampledTexture() {
+  AddSampledTexture();
+  is_multisampled_ = true;
+}
+
+void Usage::AddDepthTexture() {
+  AddSampledTexture();
+  is_depth_ = true;
+}
+
+}  // namespace spirv
+}  // namespace reader
+}  // namespace tint
diff --git a/src/reader/spirv/usage.h b/src/reader/spirv/usage.h
new file mode 100644
index 0000000000..370b6a6631
--- /dev/null
+++ b/src/reader/spirv/usage.h
@@ -0,0 +1,130 @@
+// Copyright 2020 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef SRC_READER_SPIRV_USAGE_H_
+#define SRC_READER_SPIRV_USAGE_H_
+
+#include <ostream>
+
+namespace tint {
+namespace reader {
+namespace spirv {
+
+/// Records the properties of a sampler or texture based on how it's used
+/// by image instructions inside function bodies.
+///
+/// For example:
+///
+///   If %X is the "Image" parameter of an OpImageWrite instruction then
+///    - The memory object declaration underlying %X will gain
+///      AddStorageWriteTexture usage
+///
+///   If %Y is the "Sampled Image" parameter of an OpImageSampleDrefExplicitLod
+///   instruction, and %Y is composed from sampler %YSam and image %YIm, then:
+///    - The memory object declaration underlying %YSam will gain
+///      AddComparisonSampler usage
+///    - The memory object declaration unederlying %YIm will gain
+///      AddSampledTexture and AddDepthTexture usages
+class Usage {
+ public:
+  Usage();
+  Usage(const Usage& other);
+  ~Usage();
+
+  /// @returns true if this usage is internally consistent
+  bool IsValid() const;
+  /// @returns true if the usage fully determines a WebGPU binding type.
+  bool IsComplete() const;
+
+  /// @returns true if this usage is a sampler usage.
+  bool IsSampler() const { return is_sampler_; }
+  /// @returns true if this usage is a comparison sampler usage.
+  bool IsComparisonSampler() const { return is_comparison_sampler_; }
+
+  /// @returns true if this usage is a texture usage.
+  bool IsTexture() const { return is_texture_; }
+  /// @returns true if this usage is a sampled texture usage.
+  bool IsSampledTexture() const { return is_sampled_; }
+  /// @returns true if this usage is a multisampled texture usage.
+  bool IsMultisampledTexture() const { return is_multisampled_; }
+  /// @returns true if this usage is a dpeth texture usage.
+  bool IsDepthTexture() const { return is_depth_; }
+  /// @returns true if this usage is a read-only storage texture
+  bool IsStorageReadTexture() const { return is_storage_read_; }
+  /// @returns true if this usage is a write-only storage texture
+  bool IsStorageWriteTexture() const { return is_storage_write_; }
+
+  /// @returns true if this is a storage texture.
+  bool IsStorageTexture() const {
+    return is_storage_read_ || is_storage_write_;
+  }
+
+  /// Emits this usage to the given stream
+  /// @param out the output stream.
+  /// @returns the modified stream.
+  std::ostream& operator<<(std::ostream& out) const;
+
+  /// Equality operator
+  /// @param other the RHS of the equality test.
+  /// @returns true if |other| is identical to *this
+  bool operator==(const Usage& other) const;
+
+  /// Adds the usages from another usage object.
+  /// @param other the other usage
+  void Add(const Usage& other);
+
+  /// Records usage as a sampler.
+  void AddSampler();
+  /// Records usage as a comparison sampler.
+  void AddComparisonSampler();
+
+  /// Records usage as a texture of some kind.
+  void AddTexture();
+  /// Records usage as a read-only storage texture.
+  void AddStorageReadTexture();
+  // Records usage as a write-only storage texture.
+  void AddStorageWriteTexture();
+  // Records usage as a sampled texture.
+  void AddSampledTexture();
+  // Records usage as a multisampled texture.
+  void AddMultisampledTexture();
+  /// Records usage as a depth texture.
+  void AddDepthTexture();
+
+ private:
+  // Sampler properties.
+  bool is_sampler_ = false;
+  // A comparison sampler is always a sampler:
+  //    |is_comparison_sampler_| implies |is_sampler_|
+  bool is_comparison_sampler_ = false;
+
+  // Texture properties.
+  // |is_texture_| is always implied by any of the others below.
+  bool is_texture_ = false;
+  bool is_sampled_ = false;
+  bool is_multisampled_ = false;  // This implies it's sampled as well.
+  bool is_depth_ = false;
+  bool is_storage_read_ = false;
+  bool is_storage_write_ = false;
+};
+
+inline std::ostream& operator<<(std::ostream& out, const Usage& u) {
+  return u.operator<<(out);
+}
+
+}  // namespace spirv
+}  // namespace reader
+}  // namespace tint
+
+#endif  // SRC_READER_SPIRV_USAGE_H_
diff --git a/src/reader/spirv/usage_test.cc b/src/reader/spirv/usage_test.cc
new file mode 100644
index 0000000000..ef50656585
--- /dev/null
+++ b/src/reader/spirv/usage_test.cc
@@ -0,0 +1,297 @@
+// Copyright 2020 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <algorithm>
+#include <sstream>
+#include <vector>
+
+#include "gmock/gmock.h"
+#include "src/reader/spirv/parser_impl_test_helper.h"
+#include "src/reader/spirv/usage.h"
+
+namespace tint {
+namespace reader {
+namespace spirv {
+namespace {
+
+using ::testing::Eq;
+
+TEST_F(SpvParserTest, Usage_Trivial_Properties) {
+  Usage u;
+  EXPECT_TRUE(u.IsValid());
+  EXPECT_FALSE(u.IsComplete());
+  EXPECT_FALSE(u.IsSampler());
+  EXPECT_FALSE(u.IsComparisonSampler());
+  EXPECT_FALSE(u.IsTexture());
+  EXPECT_FALSE(u.IsSampledTexture());
+  EXPECT_FALSE(u.IsMultisampledTexture());
+  EXPECT_FALSE(u.IsDepthTexture());
+  EXPECT_FALSE(u.IsStorageReadTexture());
+  EXPECT_FALSE(u.IsStorageWriteTexture());
+}
+
+TEST_F(SpvParserTest, Usage_Trivial_Output) {
+  std::ostringstream ss;
+  Usage u;
+  ss << u;
+  EXPECT_THAT(ss.str(), Eq("Usage()"));
+}
+
+TEST_F(SpvParserTest, Usage_Equality_OneDifference) {
+  const int num_usages = 9;
+  std::vector<Usage> usages(num_usages);
+  usages[1].AddSampler();
+  usages[2].AddComparisonSampler();
+  usages[3].AddTexture();
+  usages[4].AddSampledTexture();
+  usages[5].AddMultisampledTexture();
+  usages[6].AddDepthTexture();
+  usages[7].AddStorageReadTexture();
+  usages[8].AddStorageWriteTexture();
+  for (int i = 0; i < num_usages; ++i) {
+    for (int j = 0; j < num_usages; ++j) {
+      const auto& lhs = usages[i];
+      const auto& rhs = usages[j];
+      if (i == j) {
+        EXPECT_TRUE(lhs == rhs);
+      } else {
+        EXPECT_FALSE(lhs == rhs);
+      }
+    }
+  }
+}
+
+TEST_F(SpvParserTest, Usage_Add) {
+  // Mix two nontrivial usages.
+  Usage a;
+  a.AddStorageReadTexture();
+
+  Usage b;
+  b.AddComparisonSampler();
+
+  a.Add(b);
+
+  EXPECT_FALSE(a.IsValid());
+  EXPECT_FALSE(a.IsComplete());
+  EXPECT_TRUE(a.IsSampler());
+  EXPECT_TRUE(a.IsComparisonSampler());
+  EXPECT_TRUE(a.IsTexture());
+  EXPECT_FALSE(a.IsSampledTexture());
+  EXPECT_FALSE(a.IsMultisampledTexture());
+  EXPECT_FALSE(a.IsDepthTexture());
+  EXPECT_TRUE(a.IsStorageReadTexture());
+  EXPECT_FALSE(a.IsStorageWriteTexture());
+
+  std::ostringstream ss;
+  ss << a;
+  EXPECT_THAT(ss.str(), Eq("Usage(Sampler( comparison )Texture( read ))"));
+}
+
+TEST_F(SpvParserTest, Usage_AddSampler) {
+  std::ostringstream ss;
+  Usage u;
+  u.AddSampler();
+
+  EXPECT_TRUE(u.IsValid());
+  EXPECT_TRUE(u.IsComplete());
+  EXPECT_TRUE(u.IsSampler());
+  EXPECT_FALSE(u.IsComparisonSampler());
+  EXPECT_FALSE(u.IsTexture());
+  EXPECT_FALSE(u.IsSampledTexture());
+  EXPECT_FALSE(u.IsMultisampledTexture());
+  EXPECT_FALSE(u.IsDepthTexture());
+  EXPECT_FALSE(u.IsStorageReadTexture());
+  EXPECT_FALSE(u.IsStorageWriteTexture());
+
+  ss << u;
+  EXPECT_THAT(ss.str(), Eq("Usage(Sampler( ))"));
+
+  // Check idempotency
+  auto copy(u);
+  u.AddSampler();
+  EXPECT_TRUE(u == copy);
+}
+
+TEST_F(SpvParserTest, Usage_AddComparisonSampler) {
+  std::ostringstream ss;
+  Usage u;
+  u.AddComparisonSampler();
+
+  EXPECT_TRUE(u.IsValid());
+  EXPECT_TRUE(u.IsComplete());
+  EXPECT_TRUE(u.IsSampler());
+  EXPECT_TRUE(u.IsComparisonSampler());
+  EXPECT_FALSE(u.IsTexture());
+  EXPECT_FALSE(u.IsSampledTexture());
+  EXPECT_FALSE(u.IsMultisampledTexture());
+  EXPECT_FALSE(u.IsDepthTexture());
+  EXPECT_FALSE(u.IsStorageReadTexture());
+  EXPECT_FALSE(u.IsStorageWriteTexture());
+
+  ss << u;
+  EXPECT_THAT(ss.str(), Eq("Usage(Sampler( comparison ))"));
+
+  auto copy(u);
+  u.AddComparisonSampler();
+  EXPECT_TRUE(u == copy);
+}
+
+TEST_F(SpvParserTest, Usage_AddTexture) {
+  std::ostringstream ss;
+  Usage u;
+  u.AddTexture();
+
+  EXPECT_TRUE(u.IsValid());
+  EXPECT_FALSE(u.IsComplete());  // Don't know if it's sampled or storage
+  EXPECT_FALSE(u.IsSampler());
+  EXPECT_FALSE(u.IsComparisonSampler());
+  EXPECT_TRUE(u.IsTexture());
+  EXPECT_FALSE(u.IsSampledTexture());
+  EXPECT_FALSE(u.IsMultisampledTexture());
+  EXPECT_FALSE(u.IsDepthTexture());
+  EXPECT_FALSE(u.IsStorageReadTexture());
+  EXPECT_FALSE(u.IsStorageWriteTexture());
+
+  ss << u;
+  EXPECT_THAT(ss.str(), Eq("Usage(Texture( ))"));
+
+  auto copy(u);
+  u.AddTexture();
+  EXPECT_TRUE(u == copy);
+}
+
+TEST_F(SpvParserTest, Usage_AddSampledTexture) {
+  std::ostringstream ss;
+  Usage u;
+  u.AddSampledTexture();
+
+  EXPECT_TRUE(u.IsValid());
+  EXPECT_TRUE(u.IsComplete());
+  EXPECT_FALSE(u.IsSampler());
+  EXPECT_FALSE(u.IsComparisonSampler());
+  EXPECT_TRUE(u.IsTexture());
+  EXPECT_TRUE(u.IsSampledTexture());
+  EXPECT_FALSE(u.IsMultisampledTexture());
+  EXPECT_FALSE(u.IsDepthTexture());
+  EXPECT_FALSE(u.IsStorageReadTexture());
+  EXPECT_FALSE(u.IsStorageWriteTexture());
+
+  ss << u;
+  EXPECT_THAT(ss.str(), Eq("Usage(Texture( is_sampled ))"));
+
+  auto copy(u);
+  u.AddSampledTexture();
+  EXPECT_TRUE(u == copy);
+}
+
+TEST_F(SpvParserTest, Usage_AddMultisampledTexture) {
+  std::ostringstream ss;
+  Usage u;
+  u.AddMultisampledTexture();
+
+  EXPECT_TRUE(u.IsValid());
+  EXPECT_TRUE(u.IsComplete());
+  EXPECT_FALSE(u.IsSampler());
+  EXPECT_FALSE(u.IsComparisonSampler());
+  EXPECT_TRUE(u.IsTexture());
+  EXPECT_TRUE(u.IsSampledTexture());
+  EXPECT_TRUE(u.IsMultisampledTexture());
+  EXPECT_FALSE(u.IsDepthTexture());
+  EXPECT_FALSE(u.IsStorageReadTexture());
+  EXPECT_FALSE(u.IsStorageWriteTexture());
+
+  ss << u;
+  EXPECT_THAT(ss.str(), Eq("Usage(Texture( is_sampled ms ))"));
+
+  auto copy(u);
+  u.AddMultisampledTexture();
+  EXPECT_TRUE(u == copy);
+}
+
+TEST_F(SpvParserTest, Usage_AddDepthTexture) {
+  std::ostringstream ss;
+  Usage u;
+  u.AddDepthTexture();
+
+  EXPECT_TRUE(u.IsValid());
+  EXPECT_TRUE(u.IsComplete());
+  EXPECT_FALSE(u.IsSampler());
+  EXPECT_FALSE(u.IsComparisonSampler());
+  EXPECT_TRUE(u.IsTexture());
+  EXPECT_TRUE(u.IsSampledTexture());
+  EXPECT_FALSE(u.IsMultisampledTexture());
+  EXPECT_TRUE(u.IsDepthTexture());
+  EXPECT_FALSE(u.IsStorageReadTexture());
+  EXPECT_FALSE(u.IsStorageWriteTexture());
+
+  ss << u;
+  EXPECT_THAT(ss.str(), Eq("Usage(Texture( is_sampled depth ))"));
+
+  auto copy(u);
+  u.AddDepthTexture();
+  EXPECT_TRUE(u == copy);
+}
+
+TEST_F(SpvParserTest, Usage_AddStorageReadTexture) {
+  std::ostringstream ss;
+  Usage u;
+  u.AddStorageReadTexture();
+
+  EXPECT_TRUE(u.IsValid());
+  EXPECT_TRUE(u.IsComplete());
+  EXPECT_FALSE(u.IsSampler());
+  EXPECT_FALSE(u.IsComparisonSampler());
+  EXPECT_TRUE(u.IsTexture());
+  EXPECT_FALSE(u.IsSampledTexture());
+  EXPECT_FALSE(u.IsMultisampledTexture());
+  EXPECT_FALSE(u.IsDepthTexture());
+  EXPECT_TRUE(u.IsStorageReadTexture());
+  EXPECT_FALSE(u.IsStorageWriteTexture());
+
+  ss << u;
+  EXPECT_THAT(ss.str(), Eq("Usage(Texture( read ))"));
+
+  auto copy(u);
+  u.AddStorageReadTexture();
+  EXPECT_TRUE(u == copy);
+}
+
+TEST_F(SpvParserTest, Usage_AddStorageWriteTexture) {
+  std::ostringstream ss;
+  Usage u;
+  u.AddStorageWriteTexture();
+
+  EXPECT_TRUE(u.IsValid());
+  EXPECT_TRUE(u.IsComplete());
+  EXPECT_FALSE(u.IsSampler());
+  EXPECT_FALSE(u.IsComparisonSampler());
+  EXPECT_TRUE(u.IsTexture());
+  EXPECT_FALSE(u.IsSampledTexture());
+  EXPECT_FALSE(u.IsMultisampledTexture());
+  EXPECT_FALSE(u.IsDepthTexture());
+  EXPECT_FALSE(u.IsStorageReadTexture());
+  EXPECT_TRUE(u.IsStorageWriteTexture());
+
+  ss << u;
+  EXPECT_THAT(ss.str(), Eq("Usage(Texture( write ))"));
+
+  auto copy(u);
+  u.AddStorageWriteTexture();
+  EXPECT_TRUE(u == copy);
+}
+
+}  // namespace
+}  // namespace spirv
+}  // namespace reader
+}  // namespace tint