Fix warnings on VS2015 x86_64 build

TBR=bungeman@google.com

Review URL: https://codereview.chromium.org/1276133002

gm/lightingshader.cpp

@@ -38,7 +38,7 @@ static SkBitmap make_hemi_normalmap(int texSize) {
                 locY = 0.0f;
                 locZ = 0.0f;
             }
-            locZ = sqrt(1.0f - locZ);
+            locZ = sqrtf(1.0f - locZ);
             unsigned char r = static_cast<unsigned char>((0.5f * locX + 0.5f) * 255);
             unsigned char g = static_cast<unsigned char>((-0.5f * locY + 0.5f) * 255);
             unsigned char b = static_cast<unsigned char>((0.5f * locZ + 0.5f) * 255);

gyp/zlib.gyp

@@ -4,6 +4,9 @@
 # found in the LICENSE file.
 
 {
+  'variables': {
+    'skia_warnings_as_errors': 0,
+  },
   'targets': [
   {
     # Only used by win, down below.

src/gpu/GrDrawTarget.cpp

@@ -256,7 +256,8 @@ void GrDrawTarget::drawPaths(const GrPipelineBuilder& pipelineBuilder,
     SkASSERT(this->caps()->shaderCaps()->pathRenderingSupport());
     SkASSERT(pathRange);
     SkASSERT(indices);
-    SkASSERT(0 == reinterpret_cast<long>(indices) % GrPathRange::PathIndexSizeInBytes(indexType));
+    SkASSERT(0 == reinterpret_cast<intptr_t>(indices) %
+             GrPathRange::PathIndexSizeInBytes(indexType));
     SkASSERT(transformValues);
 
     // Setup clip

tests/GrMemoryPoolTest.cpp

@@ -106,12 +106,12 @@ public:
         fB = new B();
     }
     virtual void setValues(int v) {
-        fVoidStar = reinterpret_cast<void*>(v);
+        fVoidStar = reinterpret_cast<void*>(static_cast<intptr_t>(v));
         this->INHERITED::setValues(v);
         fB->setValues(v);
     }
     virtual bool checkValues(int v) {
-        return fVoidStar == reinterpret_cast<void*>(v) &&
+        return fVoidStar == reinterpret_cast<void*>(static_cast<intptr_t>(v)) &&
                fB->checkValues(v) &&
                this->INHERITED::checkValues(v);
     }