Add UniqueID to GrDrawTargetCaps.

This is needed for creating the Optimized Draw State and checking that we have the same caps
on subsequent calls to ODS

BUG=skia:
R=bsalomon@google.com

Author: egdaniel@google.com

Review URL: https://codereview.chromium.org/585043002

2 files changed, 28 insertions, 2 deletions

diff --git a/src/gpu/GrDrawTarget.cpp b/src/gpu/GrDrawTarget.cpp
index af00ac8db1..e942d7cf31 100644
--- a/src/gpu/GrDrawTarget.cpp
+++ b/src/gpu/GrDrawTarget.cpp
@@ -1147,3 +1147,13 @@ SkString GrDrawTargetCaps::dump() const {
 
     return r;
 }
+
+uint32_t GrDrawTargetCaps::CreateUniqueID() {
+    static int32_t gUniqueID = SK_InvalidUniqueID;
+    uint32_t id;
+    do {
+        id = static_cast<uint32_t>(sk_atomic_inc(&gUniqueID) + 1);
+    } while (id == SK_InvalidUniqueID);
+    return id;
+}
+
diff --git a/src/gpu/GrDrawTargetCaps.h b/src/gpu/GrDrawTargetCaps.h
index 1a3a84cf28..e468bc41ab 100644
--- a/src/gpu/GrDrawTargetCaps.h
+++ b/src/gpu/GrDrawTargetCaps.h
@@ -19,8 +19,12 @@ class GrDrawTargetCaps : public SkRefCnt {
 public:
     SK_DECLARE_INST_COUNT(GrDrawTargetCaps)
 
-    GrDrawTargetCaps() { this->reset(); }
-    GrDrawTargetCaps(const GrDrawTargetCaps& other) : INHERITED() { *this = other; }
+    GrDrawTargetCaps() : fUniqueID(CreateUniqueID()) {
+        this->reset();
+    }
+    GrDrawTargetCaps(const GrDrawTargetCaps& other) : INHERITED(), fUniqueID(CreateUniqueID()) {
+        *this = other;
+    }
     GrDrawTargetCaps& operator= (const GrDrawTargetCaps&);
 
     virtual void reset();
@@ -77,6 +81,13 @@ public:
         return fConfigTextureSupport[config];
     }
 
+    /**
+     * Gets an id that is unique for this GrDrawTargetCaps object. It is static in that it does
+     * not change when the content of the GrDrawTargetCaps object changes. This will never return
+     * 0.
+     */
+    uint32_t getUniqueID() const { return fUniqueID; }
+
 protected:
     bool fNPOTTextureTileSupport    : 1;
     bool fMipMapSupport             : 1;
@@ -103,6 +114,11 @@ protected:
     bool fConfigRenderSupport[kGrPixelConfigCnt][2];
     bool fConfigTextureSupport[kGrPixelConfigCnt];
 
+private:
+    static uint32_t CreateUniqueID();
+
+    const uint32_t          fUniqueID;
+
     typedef SkRefCnt INHERITED;
 };