Corrections for big usage table support in L3

[ Merge of http://go/wvgerrit/26421 ]

* Corrects usage_table_header lifetime management. Earlier the
  UsageTableHeader class was a singleton tied to the CdmEngine lifetime.
  With SPOIDs there might be multiple concurrent CdmEngine objects.
  The UsageTableHeader class is now associated with OEMCrypto
  lifetime. There are two UsageTableHeader objects one for each L1 and L3.
  These get allocated/deallocated on OEMCrypto Initialization/Termination
  respectively.
* UsageTableHeader requires OEMCrypto, file read/writes and
  metric gathering to perform its required functionality. Because of the
  lifetime changes, CryptoSession, DeviceFiles and MetricsGroup objects
  need to passed to the methods rather than at Creation time.
* Miscellaneous fixes, when moving or deleteing entries.
* Adds usage_table_header_unittests.
* Addresses failures with request_license_test with secure stop in L3.

b/36858906
b/36855557
b/36048120
b/38341136
b/37100505
b/35946047

Test: Verified by unit and integration tests. Added new
      usage_table_header_unittests

Change-Id: I20e396ab2c0afbd14372dd93b969e5b0f1ccd291

libwvdrmengine/cdm/core/include/crypto_session.h

@@ -17,6 +17,8 @@
 namespace wvcdm {
 
 class CryptoKey;
+class UsageTableHeader;
+
 typedef std::map<CryptoKeyId, CryptoKey*> CryptoKeyMap;
 
 class CryptoSession {
@@ -142,6 +144,9 @@ class CryptoSession {
                                         const std::string& signature);
 
   // Usage table header and usage entry related methods
+  virtual UsageTableHeader* GetUsageTableHeader() {
+    return usage_table_header_;
+  }
   virtual CdmResponseType GetUsageSupportType(CdmUsageSupportType* type);
   virtual CdmResponseType CreateUsageTableHeader(
       CdmUsageTableHeader* usage_table_header);
@@ -217,6 +222,9 @@ class CryptoSession {
 
   bool is_usage_support_type_valid_;
   CdmUsageSupportType usage_support_type_;
+  UsageTableHeader* usage_table_header_;
+  static UsageTableHeader* usage_table_header_l1_;
+  static UsageTableHeader* usage_table_header_l3_;
 
   uint64_t request_id_base_;
   static uint64_t request_id_index_;