Fix some linux build warnings
Review URL: https://codereview.appspot.com/6571050

git-svn-id: http://skia.googlecode.com/svn/trunk@5675 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrContext.cpp b/src/gpu/GrContext.cpp
index f35e729..7eb3422 100644
--- a/src/gpu/GrContext.cpp
+++ b/src/gpu/GrContext.cpp
@@ -1388,10 +1388,13 @@
     }
     // Perform any conversions we weren't able to perfom using a scratch texture.
     if (unpremul || swapRAndB || flipY) {
-        SkCanvas::Config8888 srcC8888;
-        SkCanvas::Config8888 dstC8888;
+        // These are initialized to suppress a warning
+        SkCanvas::Config8888 srcC8888 = SkCanvas::kNative_Premul_Config8888;
+        SkCanvas::Config8888 dstC8888 = SkCanvas::kNative_Premul_Config8888;
+
         bool c8888IsValid = grconfig_to_config8888(config, false, &srcC8888);
         grconfig_to_config8888(config, unpremul, &dstC8888);
+
         if (swapRAndB) {
             GrAssert(c8888IsValid); // we should only do r/b swap on 8888 configs
             srcC8888 = swap_config8888_red_and_blue(srcC8888);