Crash intentionally when requestTiles with invalid key.

This should not happen and BrowserViewRenderer/GlobalTileManager would
be in an invalid state when it happens.
Remove this CHECK before we ship L.

BUG: 17369933

Change-Id: I288b67ac9a8bd018aed207decabb37de41889a73

android_webview/browser/browser_view_renderer.cc

@@ -197,7 +197,12 @@ void BrowserViewRenderer::RequestMemoryPolicy(
   GlobalTileManager* manager = GlobalTileManager::GetInstance();
 
   // The following line will call BrowserViewRenderer::SetTilesNum().
-  manager->RequestTiles(new_policy.num_resources_limit, tile_manager_key_);
+  bool success =
+      manager->RequestTiles(new_policy.num_resources_limit, tile_manager_key_);
+  CHECK(success) << "tile_manager_key_ is invalid."
+      << "\n Current memory policy: bytes_limit " << memory_policy_.bytes_limit
+      << " num_resources_limit " << memory_policy_.num_resources_limit
+      << "\n hardware enabled " << hardware_enabled_;
 }
 
 void BrowserViewRenderer::SetNumTiles(size_t num_tiles,

android_webview/browser/global_tile_manager.cc

@@ -64,9 +64,12 @@ void GlobalTileManager::SetTileLimit(size_t num_tiles_limit) {
   num_tiles_limit_ = num_tiles_limit;
 }
 
-void GlobalTileManager::RequestTiles(size_t new_num_of_tiles, Key key) {
+bool GlobalTileManager::RequestTiles(size_t new_num_of_tiles, Key key) {
   DCHECK(IsConsistent());
   DCHECK(sequence_checker_.CalledOnValidSequencedThread());
+  if (std::find(mru_list_.begin(), mru_list_.end(), *key) == mru_list_.end()) {
+    return false;
+  }
   size_t old_num_of_tiles = (*key)->GetNumTiles();
   size_t num_of_active_views = std::distance(mru_list_.begin(), key) + 1;
   size_t tiles_per_view_limit;
@@ -81,7 +84,7 @@ void GlobalTileManager::RequestTiles(size_t new_num_of_tiles, Key key) {
   if (new_total_allocated_tiles <= num_tiles_limit_) {
     total_allocated_tiles_ = new_total_allocated_tiles;
     (*key)->SetNumTiles(new_num_of_tiles, false);
-    return;
+    return true;
   }
 
   // Does not have enough tiles. Now evict other clients' tiles.
@@ -93,11 +96,11 @@ void GlobalTileManager::RequestTiles(size_t new_num_of_tiles, Key key) {
     new_total_allocated_tiles -= evicted_tiles;
     total_allocated_tiles_ = new_total_allocated_tiles;
     (*key)->SetNumTiles(new_num_of_tiles, false);
-    return;
+    return true;
   } else {
     total_allocated_tiles_ = num_tiles_limit_;
     (*key)->SetNumTiles(tiles_left + old_num_of_tiles + evicted_tiles, false);
-    return;
+    return true;
   }
 }
 

android_webview/browser/global_tile_manager.h

@@ -36,7 +36,8 @@ class GlobalTileManager {
   // tiles are available for the client. If the number of tiles left is not
   // enough to satisfy the request, the manager will evict tiles allocated to
   // other clients.
-  void RequestTiles(size_t new_num_of_tiles, Key key);
+  // Returns false if the key cannot be found in |mru_list_|.
+  bool RequestTiles(size_t new_num_of_tiles, Key key);
 
   Key PushBack(GlobalTileManagerClient* client);