diff --git a/opengl/libs/EGL/BlobCache.cpp b/opengl/libs/EGL/BlobCache.cpp
index beca7f1..86c788d 100644
--- a/opengl/libs/EGL/BlobCache.cpp
+++ b/opengl/libs/EGL/BlobCache.cpp
@@ -52,35 +52,37 @@
     ALOGV("initializing random seed using %lld", (unsigned long long)now);
 }
 
-void BlobCache::set(const void* key, size_t keySize, const void* value, size_t valueSize) {
+BlobCache::InsertResult BlobCache::set(const void* key, size_t keySize, const void* value,
+                                       size_t valueSize) {
     if (mMaxKeySize < keySize) {
         ALOGV("set: not caching because the key is too large: %zu (limit: %zu)", keySize,
               mMaxKeySize);
-        return;
+        return InsertResult::kKeyTooBig;
     }
     if (mMaxValueSize < valueSize) {
         ALOGV("set: not caching because the value is too large: %zu (limit: %zu)", valueSize,
               mMaxValueSize);
-        return;
+        return InsertResult::kValueTooBig;
     }
     if (mMaxTotalSize < keySize + valueSize) {
         ALOGV("set: not caching because the combined key/value size is too "
               "large: %zu (limit: %zu)",
               keySize + valueSize, mMaxTotalSize);
-        return;
+        return InsertResult::kCombinedTooBig;
     }
     if (keySize == 0) {
         ALOGW("set: not caching because keySize is 0");
-        return;
+        return InsertResult::kInvalidKeySize;
     }
-    if (valueSize <= 0) {
+    if (valueSize == 0) {
         ALOGW("set: not caching because valueSize is 0");
-        return;
+        return InsertResult::kInvalidValueSize;
     }
 
     std::shared_ptr<Blob> cacheKey(new Blob(key, keySize, false));
     CacheEntry cacheEntry(cacheKey, nullptr);
 
+    bool didClean = false;
     while (true) {
         auto index = std::lower_bound(mCacheEntries.begin(), mCacheEntries.end(), cacheEntry);
         if (index == mCacheEntries.end() || cacheEntry < *index) {
@@ -92,13 +94,14 @@
                 if (isCleanable()) {
                     // Clean the cache and try again.
                     clean();
+                    didClean = true;
                     continue;
                 } else {
                     ALOGV("set: not caching new key/value pair because the "
                           "total cache size limit would be exceeded: %zu "
                           "(limit: %zu)",
                           keySize + valueSize, mMaxTotalSize);
-                    break;
+                    return InsertResult::kNotEnoughSpace;
                 }
             }
             mCacheEntries.insert(index, CacheEntry(keyBlob, valueBlob));
@@ -114,12 +117,13 @@
                 if (isCleanable()) {
                     // Clean the cache and try again.
                     clean();
+                    didClean = true;
                     continue;
                 } else {
                     ALOGV("set: not caching new value because the total cache "
                           "size limit would be exceeded: %zu (limit: %zu)",
                           keySize + valueSize, mMaxTotalSize);
-                    break;
+                    return InsertResult::kNotEnoughSpace;
                 }
             }
             index->setValue(valueBlob);
@@ -128,7 +132,7 @@
                   "value",
                   keySize, valueSize);
         }
-        break;
+        return didClean ? InsertResult::kDidClean : InsertResult::kInserted;
     }
 }
 
diff --git a/opengl/libs/EGL/BlobCache.h b/opengl/libs/EGL/BlobCache.h
index 50b4e4c..ff03d30 100644
--- a/opengl/libs/EGL/BlobCache.h
+++ b/opengl/libs/EGL/BlobCache.h
@@ -39,6 +39,26 @@
     // (key sizes plus value sizes) will not exceed maxTotalSize.
     BlobCache(size_t maxKeySize, size_t maxValueSize, size_t maxTotalSize);
 
+    // Return value from set(), below.
+    enum class InsertResult {
+        // The key is larger than maxKeySize specified in the constructor.
+        kKeyTooBig,
+        // The value is larger than maxValueSize specified in the constructor.
+        kValueTooBig,
+        // The combined key + value is larger than maxTotalSize specified in the constructor.
+        kCombinedTooBig,
+        // keySize is 0
+        kInvalidKeySize,
+        // valueSize is 0
+        kInvalidValueSize,
+        // Unable to free enough space to fit the new entry.
+        kNotEnoughSpace,
+        // The new entry was inserted, but an old entry had to be evicted.
+        kDidClean,
+        // There was enough room in the cache and the new entry was inserted.
+        kInserted,
+
+    };
     // set inserts a new binary value into the cache and associates it with the
     // given binary key.  If the key or value are too large for the cache then
     // the cache remains unchanged.  This includes the case where a different
@@ -54,7 +74,7 @@
     //   0 < keySize
     //   value != NULL
     //   0 < valueSize
-    void set(const void* key, size_t keySize, const void* value, size_t valueSize);
+    InsertResult set(const void* key, size_t keySize, const void* value, size_t valueSize);
 
     // get retrieves from the cache the binary value associated with a given
     // binary key.  If the key is present in the cache then the length of the
diff --git a/opengl/libs/EGL/BlobCache_test.cpp b/opengl/libs/EGL/BlobCache_test.cpp
index d31373b..ceea0fb 100644
--- a/opengl/libs/EGL/BlobCache_test.cpp
+++ b/opengl/libs/EGL/BlobCache_test.cpp
@@ -49,7 +49,7 @@
 
 TEST_F(BlobCacheTest, CacheSingleValueSucceeds) {
     unsigned char buf[4] = {0xee, 0xee, 0xee, 0xee};
-    mBC->set("abcd", 4, "efgh", 4);
+    ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set("abcd", 4, "efgh", 4));
     ASSERT_EQ(size_t(4), mBC->get("abcd", 4, buf, 4));
     ASSERT_EQ('e', buf[0]);
     ASSERT_EQ('f', buf[1]);
@@ -59,8 +59,8 @@
 
 TEST_F(BlobCacheTest, CacheTwoValuesSucceeds) {
     unsigned char buf[2] = {0xee, 0xee};
-    mBC->set("ab", 2, "cd", 2);
-    mBC->set("ef", 2, "gh", 2);
+    ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set("ab", 2, "cd", 2));
+    ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set("ef", 2, "gh", 2));
     ASSERT_EQ(size_t(2), mBC->get("ab", 2, buf, 2));
     ASSERT_EQ('c', buf[0]);
     ASSERT_EQ('d', buf[1]);
@@ -71,7 +71,7 @@
 
 TEST_F(BlobCacheTest, GetOnlyWritesInsideBounds) {
     unsigned char buf[6] = {0xee, 0xee, 0xee, 0xee, 0xee, 0xee};
-    mBC->set("abcd", 4, "efgh", 4);
+    ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set("abcd", 4, "efgh", 4));
     ASSERT_EQ(size_t(4), mBC->get("abcd", 4, buf + 1, 4));
     ASSERT_EQ(0xee, buf[0]);
     ASSERT_EQ('e', buf[1]);
@@ -83,7 +83,7 @@
 
 TEST_F(BlobCacheTest, GetOnlyWritesIfBufferIsLargeEnough) {
     unsigned char buf[3] = {0xee, 0xee, 0xee};
-    mBC->set("abcd", 4, "efgh", 4);
+    ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set("abcd", 4, "efgh", 4));
     ASSERT_EQ(size_t(4), mBC->get("abcd", 4, buf, 3));
     ASSERT_EQ(0xee, buf[0]);
     ASSERT_EQ(0xee, buf[1]);
@@ -91,14 +91,14 @@
 }
 
 TEST_F(BlobCacheTest, GetDoesntAccessNullBuffer) {
-    mBC->set("abcd", 4, "efgh", 4);
+    ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set("abcd", 4, "efgh", 4));
     ASSERT_EQ(size_t(4), mBC->get("abcd", 4, nullptr, 0));
 }
 
 TEST_F(BlobCacheTest, MultipleSetsCacheLatestValue) {
     unsigned char buf[4] = {0xee, 0xee, 0xee, 0xee};
-    mBC->set("abcd", 4, "efgh", 4);
-    mBC->set("abcd", 4, "ijkl", 4);
+    ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set("abcd", 4, "efgh", 4));
+    ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set("abcd", 4, "ijkl", 4));
     ASSERT_EQ(size_t(4), mBC->get("abcd", 4, buf, 4));
     ASSERT_EQ('i', buf[0]);
     ASSERT_EQ('j', buf[1]);
@@ -108,8 +108,8 @@
 
 TEST_F(BlobCacheTest, SecondSetKeepsFirstValueIfTooLarge) {
     unsigned char buf[MAX_VALUE_SIZE + 1] = {0xee, 0xee, 0xee, 0xee};
-    mBC->set("abcd", 4, "efgh", 4);
-    mBC->set("abcd", 4, buf, MAX_VALUE_SIZE + 1);
+    ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set("abcd", 4, "efgh", 4));
+    ASSERT_EQ(BlobCache::InsertResult::kValueTooBig, mBC->set("abcd", 4, buf, MAX_VALUE_SIZE + 1));
     ASSERT_EQ(size_t(4), mBC->get("abcd", 4, buf, 4));
     ASSERT_EQ('e', buf[0]);
     ASSERT_EQ('f', buf[1]);
@@ -123,7 +123,7 @@
     for (int i = 0; i < MAX_KEY_SIZE + 1; i++) {
         key[i] = 'a';
     }
-    mBC->set(key, MAX_KEY_SIZE + 1, "bbbb", 4);
+    ASSERT_EQ(BlobCache::InsertResult::kKeyTooBig, mBC->set(key, MAX_KEY_SIZE + 1, "bbbb", 4));
     ASSERT_EQ(size_t(0), mBC->get(key, MAX_KEY_SIZE + 1, buf, 4));
     ASSERT_EQ(0xee, buf[0]);
     ASSERT_EQ(0xee, buf[1]);
@@ -136,7 +136,7 @@
     for (int i = 0; i < MAX_VALUE_SIZE + 1; i++) {
         buf[i] = 'b';
     }
-    mBC->set("abcd", 4, buf, MAX_VALUE_SIZE + 1);
+    ASSERT_EQ(BlobCache::InsertResult::kValueTooBig, mBC->set("abcd", 4, buf, MAX_VALUE_SIZE + 1));
     for (int i = 0; i < MAX_VALUE_SIZE + 1; i++) {
         buf[i] = 0xee;
     }
@@ -163,7 +163,8 @@
         buf[i] = 'b';
     }
 
-    mBC->set(key, MAX_KEY_SIZE, buf, MAX_VALUE_SIZE);
+    ASSERT_EQ(BlobCache::InsertResult::kCombinedTooBig,
+              mBC->set(key, MAX_KEY_SIZE, buf, MAX_VALUE_SIZE));
     ASSERT_EQ(size_t(0), mBC->get(key, MAX_KEY_SIZE, nullptr, 0));
 }
 
@@ -173,7 +174,7 @@
     for (int i = 0; i < MAX_KEY_SIZE; i++) {
         key[i] = 'a';
     }
-    mBC->set(key, MAX_KEY_SIZE, "wxyz", 4);
+    ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set(key, MAX_KEY_SIZE, "wxyz", 4));
     ASSERT_EQ(size_t(4), mBC->get(key, MAX_KEY_SIZE, buf, 4));
     ASSERT_EQ('w', buf[0]);
     ASSERT_EQ('x', buf[1]);
@@ -186,7 +187,7 @@
     for (int i = 0; i < MAX_VALUE_SIZE; i++) {
         buf[i] = 'b';
     }
-    mBC->set("abcd", 4, buf, MAX_VALUE_SIZE);
+    ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set("abcd", 4, buf, MAX_VALUE_SIZE));
     for (int i = 0; i < MAX_VALUE_SIZE; i++) {
         buf[i] = 0xee;
     }
@@ -212,13 +213,45 @@
         buf[i] = 'b';
     }
 
-    mBC->set(key, MAX_KEY_SIZE, buf, bufSize);
+    ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set(key, MAX_KEY_SIZE, buf, bufSize));
     ASSERT_EQ(size_t(bufSize), mBC->get(key, MAX_KEY_SIZE, nullptr, 0));
 }
 
+// Verify that kNotEnoughSpace is returned from BlobCache::set when expected.
+// Note: This relies on internal knowledge of how BlobCache works.
+TEST_F(BlobCacheTest, NotEnoughSpace) {
+    // Insert a small entry into the cache.
+    ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set("x", 1, "y", 1));
+
+    // Attempt to put a max size entry into the cache. If the cache were empty,
+    // as in CacheMaxKeyValuePairSizeSucceeds, this would succeed. Based on the
+    // current logic of BlobCache, the small entry is not big enough to allow it
+    // to be cleaned to insert the new entry.
+    ASSERT_TRUE(MAX_KEY_SIZE < MAX_TOTAL_SIZE);
+
+    enum { bufSize = MAX_TOTAL_SIZE - MAX_KEY_SIZE };
+
+    char key[MAX_KEY_SIZE];
+    char buf[bufSize];
+    for (int i = 0; i < MAX_KEY_SIZE; i++) {
+        key[i] = 'a';
+    }
+    for (int i = 0; i < bufSize; i++) {
+        buf[i] = 'b';
+    }
+
+    ASSERT_EQ(BlobCache::InsertResult::kNotEnoughSpace, mBC->set(key, MAX_KEY_SIZE, buf, bufSize));
+    ASSERT_EQ(0, mBC->get(key, MAX_KEY_SIZE, nullptr, 0));
+
+    // The original entry remains in the cache.
+    unsigned char buf2[1] = {0xee};
+    ASSERT_EQ(size_t(1), mBC->get("x", 1, buf2, 1));
+    ASSERT_EQ('y', buf2[0]);
+}
+
 TEST_F(BlobCacheTest, CacheMinKeyAndValueSizeSucceeds) {
     unsigned char buf[1] = {0xee};
-    mBC->set("x", 1, "y", 1);
+    ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set("x", 1, "y", 1));
     ASSERT_EQ(size_t(1), mBC->get("x", 1, buf, 1));
     ASSERT_EQ('y', buf[0]);
 }
@@ -243,12 +276,12 @@
     const int maxEntries = MAX_TOTAL_SIZE / 2;
     for (int i = 0; i < maxEntries; i++) {
         uint8_t k = i;
-        mBC->set(&k, 1, "x", 1);
+        ASSERT_EQ(BlobCache::InsertResult::kInserted, mBC->set(&k, 1, "x", 1));
     }
     // Insert one more entry, causing a cache overflow.
     {
         uint8_t k = maxEntries;
-        mBC->set(&k, 1, "x", 1);
+        ASSERT_EQ(BlobCache::InsertResult::kDidClean, mBC->set(&k, 1, "x", 1));
     }
     // Count the number of entries in the cache.
     int numCached = 0;
@@ -261,6 +294,14 @@
     ASSERT_EQ(maxEntries / 2 + 1, numCached);
 }
 
+TEST_F(BlobCacheTest, InvalidKeySize) {
+    ASSERT_EQ(BlobCache::InsertResult::kInvalidKeySize, mBC->set("", 0, "efgh", 4));
+}
+
+TEST_F(BlobCacheTest, InvalidValueSize) {
+    ASSERT_EQ(BlobCache::InsertResult::kInvalidValueSize, mBC->set("abcd", 4, "", 0));
+}
+
 class BlobCacheFlattenTest : public BlobCacheTest {
 protected:
     virtual void SetUp() {