--- a/dom/media/omx/OMXCodecWrapper.cpp
+++ b/dom/media/omx/OMXCodecWrapper.cpp
@@ -282,21 +282,21 @@ ConvertPlanarYCbCrToNV12(const PlanarYCb
              ySize.height % uvSize.height == 0);
   size_t uvWidth = ySize.width / 2;
   size_t uvHeight = ySize.height / 2;
   size_t horiSubsample = uvSize.width / uvWidth;
   size_t uPixStride = horiSubsample * (1 + aSource->mCbSkip);
   size_t vPixStride = horiSubsample * (1 + aSource->mCrSkip);
   size_t lineStride = uvSize.height / uvHeight * aSource->mCbCrStride;
 
-  for (int i = 0; i < uvHeight; i++) {
+  for (size_t i = 0; i < uvHeight; i++) {
     // 1st pixel per line.
     uint8_t* uSrc = u;
     uint8_t* vSrc = v;
-    for (int j = 0; j < uvWidth; j++) {
+    for (size_t j = 0; j < uvWidth; j++) {
       *aDestination++ = *uSrc;
       *aDestination++ = *vSrc;
       // Pick next source pixel.
       uSrc += uPixStride;
       vSrc += vPixStride;
     }
     // Pick next source line.
     u += lineStride;

--- a/dom/media/omx/mediaresourcemanager/MediaResourceManagerService.cpp
+++ b/dom/media/omx/mediaresourcemanager/MediaResourceManagerService.cpp
@@ -328,17 +328,17 @@ status_t MediaResourceManagerService::Re
   Fifo& queue = mMap.editValueAt(found).mRequestQueue;
   queue.erase(queue.begin());
   return OK;
 }
 
 status_t MediaResourceManagerService::ResourceTable::forgetClient(const sp<IBinder>& client)
 {
   // Traverse all resources.
-  for (int i = 0; i < mMap.size(); i++) {
+  for (size_t i = 0; i < mMap.size(); i++) {
     forgetClient(client, mMap.keyAt(i));
   }
   return OK;
 }
 
 status_t MediaResourceManagerService::ResourceTable::forgetClient(const sp<IBinder>& client, ResourceType type)
 {
   MOZ_ASSERT(supportsType(type));
@@ -353,17 +353,17 @@ status_t MediaResourceManagerService::Re
       queue.erase(it);
       break;
     }
     it++;
   }
 
   // Revoke ownership for given client.
   Slots& slots = resources.mSlots;
-  for (int i = 0; i < slots.size(); i++) {
+  for (size_t i = 0; i < slots.size(); i++) {
     ResourceSlot& slot = slots.editItemAt(i);
     if (client.get() == slot.mClient.get()) {
       slot.mClient = nullptr;
     }
   }
 
   return OK;
 }