Bug 1352093 - Use an integer type for sNumLivingContexts that won't overflow when counting objects. r=mstange

MozReview-Commit-ID: 2w9y0flEdrX

--HG--
extra : rebase_source : 199beffa993b756ef208f6070a9f5c3de0d2fea0

dom/canvas/CanvasRenderingContext2D.cpp

@@ -1081,7 +1081,7 @@ NS_INTERFACE_MAP_END
 
 
 // Initialize our static variables.
-uint32_t CanvasRenderingContext2D::sNumLivingContexts = 0;
+uintptr_t CanvasRenderingContext2D::sNumLivingContexts = 0;
 DrawTarget* CanvasRenderingContext2D::sErrorTarget = nullptr;
 static bool sMaxContextsInitialized = false;
 static int32_t sMaxContexts = 0;

dom/canvas/CanvasRenderingContext2D.h

@@ -578,7 +578,7 @@ protected:
     * The number of living nsCanvasRenderingContexts.  When this goes down to
     * 0, we free the premultiply and unpremultiply tables, if they exist.
     */
-  static uint32_t sNumLivingContexts;
+  static uintptr_t sNumLivingContexts;
 
   static mozilla::gfx::DrawTarget* sErrorTarget;