histograms for gpu program cache

gpu/command_buffer/service/memory_program_cache.cc

Index: gpu/command_buffer/service/memory_program_cache.cc
diff --git a/gpu/command_buffer/service/memory_program_cache.cc b/gpu/command_buffer/service/memory_program_cache.cc
index e669ac4f83bff1ebf9befce164a102f509a2a647..0d51d1779cf41b8fa52fecbd9cccfb5da5c1e982 100644
--- a/gpu/command_buffer/service/memory_program_cache.cc
+++ b/gpu/command_buffer/service/memory_program_cache.cc
@@ -100,6 +100,7 @@ void MemoryProgramCache::SaveLinkedProgram(
                      NULL,
                      &format,
                      binary.get());
+  UMA_HISTOGRAM_COUNTS("GPU.ProgramCache.ProgramBinarySizeBytes", length);
 
   char a_sha[kHashLength];
   char b_sha[kHashLength];
@@ -113,6 +114,9 @@ void MemoryProgramCache::SaveLinkedProgram(
                      sha);
   const std::string sha_string(sha, sizeof(sha));
 
+  UMA_HISTOGRAM_COUNTS("GPU.ProgramCache.MemorySizeBeforeKb",
+                       curr_size_bytes_ / 1024);
+
   if (store_.find(sha_string) != store_.end()) {
     const StoreMap::iterator found = store_.find(sha_string);
     const ProgramCacheValue* evicting = found->second;
@@ -142,6 +146,10 @@ void MemoryProgramCache::SaveLinkedProgram(
                                              shader_b->uniform_map());
   curr_size_bytes_ += length;
   eviction_helper_.KeyUsed(sha_string);
+
+  UMA_HISTOGRAM_COUNTS("GPU.ProgramCache.MemorySizeAfterKb",
+                         curr_size_bytes_ / 1024);
+
   LinkedProgramCacheSuccess(sha_string,
                             std::string(a_sha, kHashLength),
                             std::string(b_sha, kHashLength));